* move not shared files (sch_item_struct.*, sch_base_frame.h) to eeschema;
* move wxEeschemaStruct.h to eeschema and rename it schframe.h to be consistent with the other corresponding file name schframe.cpp;
* remove few not needed  #include

* Remove redundant number from unit context menu.
* Use letters instead of numbers in component edit dialog.

Road map: Gerber X2 file function extension marked done in Pcbnew and Gerbview

IO_MGR::PCB_FILE_T IO_MGR::GuessPluginTypeFromLibPath() : better test for KICAD type footprint libraries: previoulsy, just test if a library name ends with .pretty, which is not enough.
GitHub lib names also ends  by .pretty, so also test if a lib name does not start by http (which could be a GitHub lib name).

Eeschema: back to KICAD_KEEPCASE option, to find parts in lib, when using case sensitive option (default).
Schematic component properties dialog: add 2 helper buttons to manage the chip name (name of the corresponding part in lib)
- a browse button to chose an other chip name
- a test button, to know if the part exists. If not existing, list the parts found when searching using a case insensitive comparison.

Kicad manager: fix an issue when starting eeschema from its button: if the library editor was previously running, and if the quasimodal field editor dialog was called, eeschema dis not start on Windows, or started but dis not load the schematic project on Linux.
Enhancement: if a tool is running but is iconized, clicking on its button bring the window on screen.

Eeschema: remove the compil option KICAD_KEEPCASE. Eeschema is now always case sensitive when seraching components in libs.
However to be compatible with old versions of Eeschema, when a search in library fails, a case insensitive search is made.
Therefore, this version should be compatible with sch files created by previous Eeschema versions compiled with KICAD_KEEPCASE = OFF

  *) When kicad.exe closes a project, close any open KIFACEs so that they cannot
     get disassociated from their true PROJECT.
  *) Allow loading eeschema library editor from kicad.exe
  *) Allow loading pcbnew library editor from kicad.exe
  *) Rename LIB_COMPONENT to LIB_PART.
  *) Add class PART_LIBS, and PART_LIB.
  *) Make PART_LIBS non-global, i.e. PROJECT specific.
  *) Implement "data on demand" for PART_LIBS
  *) Implement "data on demand" for schematic SEARCH_STACK.
  *) Use RSTRINGs to retain eeschema editor's notion of last library and part being edited.
  *) Get rid of library search on every SCH_COMPONENT::Draw() call, instead use
     a weak pointer.
  *) Remove all chdir() calls so projects don't need to be CWD.
  *) Romove APPEND support from OpenProjectFiles().
  *) Make OpenProjectFiles() robust, even for creating new projects.
  *) Load EESCHEMA colors in the KIWAY::OnKiwayStart() rather in window open,
     and save them in the .eeschema config file, not in the project file.
  *) Fix bug with wxDir() while accessing protected dirs in kicad.exe
  *) Consolidate template copying into PROJECT class, not in kicad.exe source.
  *) Generally untangle eeschema, making its libraries not global but rather
     held in the PROJECT.

*) Eeschema can now show the footprint editor.

*) Eeschema can now invoke the footprint picker from the library part field editor.

*) KIWAY_PLAYER::ShowModal() takes aResultantFocusWindow that tells what window
   to give the focus to.  Required since frames are often near the top of the
   hierarchy and they are invoked by a peer, not a parent.

*) Eeschema can now show the footprint editor.

*) Eeschema can now invoke the footprint picker from the library part field editor.

*) KIWAY_PLAYER::ShowModal() takes aResultantFocusWindow that tells what window
   to give the focus to.  Required since frames are often near the top of the
   hierarchy and they are invoked by a peer, not a parent.

*) KIWAY_PLAYER::IsModal() is now a retained state, controlled by SetModal()

*) Fully re-work the KIWAY_PLAYER::ShowModal() to use a nested event loop.

*) Add support to DIALOG_SHIM for a "quasi-modal" dialog presentation and mode.
   See top of dialog_shim.cpp about that for benefits and need.

*) You can now pick footprint from the schematic component field dialog, although
   if you do this before you open the BOARD, you will only get the global footprint
   libraries, not also the project specific ones.  Opening the BOARD first avoids this
   problem.

This is the first example of cross KIFACE invocation, it is also the first
instance of using a TOP_FRAME other than FRAME_PCB as the first thing. It works,
but it's missing support for opening the project specific table because
historically the FRAME_PCB did that. This is now starting to expose all the near
term needs for KIWAY_PLAYER <-> PROJECT interaction, independence and out of
sequence usage.

A fix for this will be coming in a few days.

However it mostly starts to show why the KIWAY is terribly useful and important.

*) KIWAY_PLAYER::IsModal() is now a retained state, controlled by SetModal()

*) Fully re-work the KIWAY_PLAYER::ShowModal() to use a nested event loop.

*) Add support to DIALOG_SHIM for a "quasi-modal" dialog presentation and mode.
   See top of dialog_shim.cpp about that for benefits and need.

*) You can now pick footprint from the schematic component field dialog, although
   if you do this before you open the BOARD, you will only get the global footprint
   libraries, not also the project specific ones.  Opening the BOARD first avoids this
   problem.

This is the first example of cross KIFACE invocation, it is also the first
instance of using a TOP_FRAME other than FRAME_PCB as the first thing. It works,
but it's missing support for opening the project specific table because
historically the FRAME_PCB did that. This is now starting to expose all the near
term needs for KIWAY_PLAYER <-> PROJECT interaction, independence and out of
sequence usage.

A fix for this will be coming in a few days.

However it mostly starts to show why the KIWAY is terribly useful and important.

!   The initial testing of this commit should be done using a Debug build so that
    all the wxASSERT()s are enabled.  Also, be sure and keep enabled the
    USE_KIWAY_DLLs option.  The tree won't likely build without it.  Turning it
    off is senseless anyways.  If you want stable code, go back to a prior version,
    the one tagged with "stable".

*   Relocate all functionality out of the wxApp derivative into more finely
    targeted purposes:
    a) DLL/DSO specific
    b) PROJECT specific
    c) EXE or process specific
    d) configuration file specific data
    e) configuration file manipulations functions.

    All of this functionality was blended into an extremely large wxApp derivative
    and that was incompatible with the desire to support multiple concurrently
    loaded DLL/DSO's ("KIFACE")s and multiple concurrently open projects.
    An amazing amount of organization come from simply sorting each bit of
    functionality into the proper box.

*   Switch to wxConfigBase from wxConfig everywhere except instantiation.
*   Add classes KIWAY, KIFACE, KIFACE_I, SEARCH_STACK, PGM_BASE, PGM_KICAD,
    PGM_SINGLE_TOP,
*   Remove "Return" prefix on many function names.
*   Remove obvious comments from CMakeLists.txt files, and from else() and endif()s.
*   Fix building boost for use in a DSO on linux.
*   Remove some of the assumptions in the CMakeLists.txt files that windows had
    to be the host platform when building windows binaries.
*   Reduce the number of wxStrings being constructed at program load time via
    static construction.
*   Pass wxConfigBase* to all SaveSettings() and LoadSettings() functions so that
    these functions are useful even when the wxConfigBase comes from another
    source, as is the case in the KICAD_MANAGER_FRAME.
*   Move the setting of the KIPRJMOD environment variable into class PROJECT,
    so that it can be moved into a project variable soon, and out of FP_LIB_TABLE.
*   Add the KIWAY_PLAYER which is associated with a particular PROJECT, and all
    its child wxFrames and wxDialogs now have a Kiway() member function which
    returns a KIWAY& that that window tree branch is in support of.  This is like
    wxWindows DNA in that child windows get this member with proper value at time
    of construction.
*   Anticipate some of the needs for milestones B) and C) and make code
    adjustments now in an effort to reduce work in those milestones.
*   No testing has been done for python scripting, since milestone C) has that
    being largely reworked and re-thought-out.

Minor change: Eeschema+Pcbnew: display timestamp in edit dialogs (for footprints, sheets, components)

Pcbnew: Fix issue when displaying net names and/or pad numbers including the "<" char in drc dialog, because drc dialog uses an wxHtmlWindow to display drc messages, and the "<" char has a special meaning and is not allowed in texts (now replaced by the" &lt;" sequence in messages displayed in html)
Eeschema: replace "<" and ">" by "(" and ")" in autogenerated net names, to avoid other issues in html messages.
Very minor other fixes.

dialogs which allow editing of component properties.  The button
is active when the table row cursor is on the DATASHEET field only.
When active, and your datasheet is a URI, then your default
browser will be launced to show that datasheet if it can find it.
This incentivizes use of http:// links for datasheets.

fix libeditframe.cpp, which in release build would not show multipart text in listbox.  dialog uses DIALOG_SHIM.

Minor changes in dialogs to ensure a better likeness between dialogs on Linux and Windows (mainly, remove some wxStaticBoxSizer in dialogs)

* Complete encapsulation of the MODULE class.
* Complete encapsulation of the EDA_TEXT class.
* Encapsulate most of the ZONE_CONTAINER class.
* Add pcbcommon library as a dependency for reSWIGging the scripting
  support.  This should cover most dependency cases.

Eeschema: All fixed fields are now always saved in libraries. Therefore the footprint field can be set in lib (size, visibility) and imported in schematic with its predefined attributes, even if the footprint text is not set.

* Move all convert from user to internal units into base_units.cpp.
* Remove internal units parameters from all moved conversion functions.
* Revise all source code that calls the moved conversion functions.
* Remove internal units from all dialog text control helper classes.

* Move all convert from internal to user units functions into separate file.
* Remove internal units parameter from all moved conversion functions.
* Revise all source code that calls the moved conversion functions.
* Compile these conversion routines separately for the appropriate pcb or
  schematic internal units.
* Move internal units specific status bar update code into the appropriate
  application for updating the status bar.
* Move millimeter user units rounding function to common.cpp.