Add EDA_BASE_FRAME::Show() and call SaveSettings() only from there for all derived wxFrames.  Remove calls to SaveSettings() elsewhere.

Mingw, all: remove static link of libgcc, which can create issues when using dll version of wxWidgets.
Therefore libgcc_s_dw2-1.dll should be in the paths for executables.

Remove wxUSE_UNICODE definition from CMakeLists.txt, because this define comes from wxWidgets and should not be made inside kicad
Remove KICAD_GOST option because it is  now useless: the 2 GOST options are now selectable at run time and are:
* specific page layouts (now user definable, and the GOST page layouts are available in template folder)
* notation for multiple parts per package (made in eeschema, preference menu)

* Remove fp_lib token from board and s-expr netlist file format.
* Fix a bunch of Doxygen warnings.
* Remove some extra debug log messages.

Pcbnew: Redesign layer selection and layer pair selection (give them a look near the Layer selector in toolbarr)

Add pl_editor_doc.icns, from Orson. Fix Bug #1217504  (bad look of Module Properties Dialog, 3D fields).
Add Dick's workaround in plot_board_layers.cpp to try to avoid crash in solder mask calculations, due to a bug in boost::polygon, in resize function.

Others: fix very minor issues.

Pl_Editor: fix copyright in files. Enhancement when creating new items.

*) add hotkey for setting the grid origin as 'S', in board editor, module editor.
*) re-position the function interface for cursor movement from BASE_SCREEN into
   class EDA_DRAW_FRAME.  This is a prelude to getting rid of BASE_SCREEN or
   splitting it up.