* 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.
* Warn the user that fields with no value and not it the field template list
will be removed from the component before exiting the edit component in
schematic dialog.
* Add a function to TEMPLATES class to check if template list contains a
field with a given name.
* Move the function to display the edit component in schematic dialog into
the SCH_EDIT_FRAME class.
* Doxygen and coding style policy fixes.