* 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.
* Fix grid select box update bug on context menu.
* Fix via size and track width select box update bugs.
* Fix layer pair indicator button update bug.
* Fix auto track width tool bar control enable bug.
* Fix via size and track width select status bug in context menu.
* Fix layer select box and layer control widget select bug when current
layer is removed.
* Add virtual function to notify objects derived from EDA_DRAW_FRAME that
the units setting has changed.
* Coding policy class naming fixes.
* Replace all known instances of (const wxChar*) casts to GetChars() for
wxWidgets 2.9 compatibility.
* Cleaned up get component dialog so last part gets saved on wild card
selections.
* Remove redundant schematic component drawing code.
* Added SCH_COMPONENT constructor to create new component from library
component object.
* Add message panel helpers to WinEDA_DrawFrame and update old message
panel access code.
* Using library viewer to add component to schematic now respects unit
and body style selection.