Fix some coverity warnings (not initialized members). Add comments. Better (more informative) title in dialog to download .pretty libs.

* 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

Pcbnew: fix bug  #142348 (airwire does not always appear after deleting a track). Very minor other fixes.

Rename eeschema/dialogs/dialog_sch_find.fbp to dialog_schematic_find_base.fbp, to be consistent with other dialogs. 
Pcbnew run from the project manager: add menu Save Copy As..., which is the same command as Save As ... in stand alone mode, but with the constraints of a project (no cwd change, no board filename change, and keep project settings)

Dialogs edit footprint in module editor and edit footprint in board editor: add button to edit the selected 3D shape filename.
Dialog edit component in library editor: add button to edit the selected footprint filter.

* Fix -Woverloaded-virtual warning in DIALOG_LIB_NEW_COMPONENT class
  definition.
* Make EDA_ITEM::Matches( const wxString& wxFindReplaceData& ) protected
  since it's a helper function that should only be called by derived objects.

Fix minor aesthetic issues in dialogs (these minor issues (overlapping widgets)  exit only with some Windows managers like KDE)

Very minor fixes: add missing const return type to some GetBoundingBox() declarations. Change few functions names to better names in some places (like GetName() to GetPinName() )

Minor and very minors fixes: move -DKICAD_USE_WEBKIT definition to the main CMakeLists.txt. Remove duplicate semi-colon at end of some lines.

* Make generate button the default in Eeschema netlist dialog.
* Fix spacing issues in export IDF dialog.
* Make OK button the default in export IDF dialog.
* Remove unnecessary end dialog code from export IDF dialog.
* Improve resizing of export IDF dialog.

* 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

BOM dialog: remove a not very useful button, and merge its function with an other (not perfect, need more work)
Add message box to show info added in BOM python scripts (See scripts/bom-in-python/README-bom.txt about this info)

Eeschema: Netlist generator: remove option to generate the fully outdated old netlist file format (based on a very old Orcad netlist format)
Only the new (S expression) better netlist file format is now used.

Try to fix issues on Ubuntu/Unity for dialogs which are not displayed: adding GetSizer()->Fit( this ) in some other dialogs

Try to fix an issue on Ubuntu/Unity for some dialogs which are not displayed. For most, adding GetSizer()->Fit( this ) in dialog constructor fix the issue, but at least one dialog still is not displayed.

* Fix assertions in Eeschema when editing net labels, electronic rules check,
  and plotting.
* Fix assertion when opening PCB calculator.
* Fix assertions in Pcbnew when changing footprints in footprint properties
  dialog and adding or editing text.

Fix many doxygen warnings (due to missing info, old comments, typo ...) when building the doxygen doc.

Eeschema, Plot dialog: add Plot directory selection. The patch from 1383026@bugs.launchpad.net was widely used.

eeschema: fix Bug #1385789 (eeschema segfaults, when editing a new field). Fix an other minor bug in Footprint editor.

Add FILE_NAME_WITH_PATH_CHAR_VALIDATOR, a custom wxValidator which allows file names with paths, in schematic sheet editor
( FILE_NAME_CHAR_VALIDATOR previously used in this dialog does not allow chars used in path names, like / and on Windows \ and : )