* Rename all ADD_MENUITEM_* functions to AddMenuItem and move them to
wxstruct.h since they are used by the Kicad main frame classes.
* Move SET_BITMAP and SETBITMAPS definitions to wxstruct.h.
* Fix a bug in SET_BITMAPS that prevented enabling menu item images on
OSX.
* Rename MsgItem to EDA_MSG_ITEM.
* Remove redundant includes from modified files.
* Doxygen and coding style policy fixes.
Added: in file dialog, multiple file selection.
Added: Draw mode selector (in left toolbar):
Raw mode:
a Gerber image is drawn on screen without buffering.
Artifacts happen if there are negative items drawn, if more than one Gerber file is shown.
Stacked mode:
each Geber image is drawn in a buffer and after drawn on screen
No artifact with negative items.
Each Gerber image covers previous images.
OR mode (transparency mode):
each Geber image is drawn in a buffer and after drawn on screen
No artifact with negative items.
Each Gerber image is "ORed" with previous images, like in Pcbnew.
Try to optimize Draw function in buffered modes.
(Useful for PC that have problems with "blit" graphic function)
Fix minor issues.