!   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.

Renamed BOARD_CONNECTED_ITEM::SetNet() -> SetNetCode()
Added BOARD_CONNECTED_ITEM::GetNet() for accessing NETINFO_ITEM* of a given item.
Fixed module editor crash when launched to edit a module from a PCB.
Replaced some BOARD::FindNet( item->GetNet() ) calls with BOARD_CONNECTED_ITEM::GetNet().

Renamed BOARD_CONNECTED_ITEM::SetNet() -> SetNetCode()
Added BOARD_CONNECTED_ITEM::GetNet() for accessing NETINFO_ITEM* of a given item.
Fixed module editor crash when launched to edit a module from a PCB.
Replaced some BOARD::FindNet( item->GetNet() ) calls with BOARD_CONNECTED_ITEM::GetNet().

- ZONE_CONTAINER::m_Netname field
- ZONE_CONTAINER::SetNetName()
- ZONE_CONTAINER::SetNet() [it uses the one in BOARD_CONNECTED_ITEM]
- ZONE_CONTAINER::GetNetName() [instead BOARD_CONNECTED_ITEM::GetNetname is used]
- ZONE_CONTAINER::SetNetNameFromNetCode()

Performed tests:
- Drawn a zone that belongs to a net, then modified schematics so the net does not exist anymore. After reloading the net list, all pads/tracks are updated. Zones still belongs to the net that does not exist in the schematic (but still exists in .kicad_pcb file). After running DRC, the zone becomes not filled.
- Undo & redo affects assignment of a polygon to a specific net (you may change net of a polygon, refill it and undo/redo the changes).

Implemented the LAYER_NUM typedef (LAYER was already taken as a class name...) to represent a layer number.

* Complete encapsulation of the ZONE_CONTAINER class.
* Fixed a bug in the EDA_TEXT::Format() default effects behavior due to
  improper conversion to internal units and missing test for default
  thickness.
* Improved grammar of some Pcbnew context menu strings.
* Moved some more cleverly hidden BOARD object methods into class_board.cpp.
* Lots of coding policy and documentation fixes.

* 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.

Some coding style policy fix.

Pcbnew: more about keepout areas: remove keepout for pads option and add keepout for copper zones option.
Export keepout to Specctra DSN file.

This is *a work in progress*, so some features are missing, and/or could be modified.
Mainly keepout zones are not yet exported to autorouters, and pads are not taken in account.
Some code cleanup in polygon.*

* Remove unnecessary copy constructors from board and module library
  objects.
* Add doClone() method to board and library objects.
* Add comment to class definitions where the default copy constructor
  generated by the compiler was adequate.
* Replace copy method with clone method where applicable.
* Remove DuplicateStruct() function.
* Remove track object copy function.

* Correct all user strings and comments for the correct capitalization of
  application names according to JP.  They are KiCad, Pcbnew, CvPcb,
  Eeschema, and GerbView.
* Add a note the the user interface policy about the correct capitalization.

* All header files used to create the PCB common library now compile as
  stand alone code.  This prevents the need to define them in a specific
  order to make source code compile properly.  It should also now be
  possible to relocate the source code to build the common PCB library
  to a separate folder.

* Move undo item copy global variable into schematic editor frame object
  member variable.
* Add helper methods for accessing the undo item copy member variable.
* Fix undetected bug when changing a text type.
* Added an exchange command to the undo/redo base class for handling undoing
  a changed item type which cannot be undone by swapping out the variables.
* Revert change to common/hotkeys_basic.cpp that broke hot key behavior.
* Lots of coding policy changes while making the changes above.

can be deleted later if they exist in the headers, or moved to 
headers if they should exist in the headers.