* Remove all occurrences if #ifdef USE_WX_ZOOM and all associated code within
the #else/#endif block ( old zoom code ).
* Removed the build option for USE_WX_ZOOM from CMakeList.txt and config.h.in.
* Removed all scaling code in base screen object.
* Fixed buffered paint and buffered client DC on Windows. Buffering works
properly on Linux and Windows.
* Modified kicad_device_context.h to automatically uses buffering on platforms
where double buffering is supported natively.
* Remove all of the scaled versions of the drawing functions in gr_basic.cpp
and any support code.
* Removed all traces of ActiveScreen global variable from eeschema and
gerbview.
* Renamed Recadre_Trace to RedrawScreen in draw frame object.
* Renamed PostDirtyRect to RefreshDrawingRect in draw panel object.
* Lots of code cleaning an Doxygen comment improvements.
* Use Boost pointer container for sheet hierarchy object.
* Add test for modification in sheet hierarchy list object.
* Add method to clear modification flag in sheet hierarchy list object.
* Improve Doxygen comments for sheet hierarchy list object.
* Remove redundant definitions in prototypes header file.
* Move schematic wire and bus break code into schematic screen object.
* Move schematic test for dangling ends into schematic screen object.
* Remove left over debugging output in schematic screen object.
* Remove unused file eeschema/cleanup.cpp.
* Fix bug in schematic line object hit test algorithm.
* Fix a string concatenation compile error added in r2752.
* Rename class WinEDA_BasicFrame to EDA_BASE_FRAME.
* Rename class WinEDA_DrawFrame to EDA_DRAW_FRAME.
* Rename class WinEDA_DrawPanel to EDA_DRAW_PANEL.
* Encapsulate file name member of base screen object.
* Encapsulate associated screen member of schematic sheet object.
* Create add screen method to schematic sheet object to simplify setting
the associated screen.
* Move the change file name code in the schematic sheet object to the edit
sheet method in the schematic editor frame object to eliminate message
dialogs.
* Improve reference counting in schematic screen object.
* Add helper type definitions for changing schematic object storage to C++
containers.
* Move schematic select block from global variable to SCH_EDIT_FRAME.
* Remove redundant schematic drawing code for eeredraw.cpp.
* Move block select code into SCH_SCREEN object.
* Simpilify block item select code.
* Fix bug in SCH_LINE selection state test.
* Add test to schematic objects for connectability.
* Make copy block items function a private method in SCH_EDIT_FRAME.
Wayne Stambaugh
Dick Hollenbeck