* Add SCH_PLUGIN::Save() for current file format and code for saving all
SCH_XXX objects.
* Add function to SCH_FIELD to get the position of the field in the component
not the position added to the component position which is what GetPosition()
does. This was required because saving the component field expects position
of the field sans the position of the component.
* Remove public members from BITMAP_BASE object and fix all associated
code.
* Fix the never ending coding policy violations found making these changes.
* EDA_DRAW_PANEL completely encapsulated.
* Moved OSX m_overlay member from EDA_DRAW_PANEL to EDA_DRAW_FRAME where
it is used.
* Doxygen comment warning fixes.