* 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.
* Rename sch_item files to sch_junction.
* Make global variable g_ItemToRepeat a private member of SCH_EDIT_FRAME
object.
* Encapsulate SCH_SCREEN reference count member.
* Change default build to enable wxDC zooming.
* Move sheet label find function into SCH_SCREEN object.
* Move draw screen items function into SCH_SCREEN object.
* Remove redundant page print method from SCH_EDIT_FRAME.
* Add method to hit test for all items in SCH_SCREEN.
* Add method for testing if junction is required in SCH_SCREEN.
* Fix Doxygen waring in help_common_strings.h
* Move update block pick list code to SCH_SCREEN object.
* Remove redundant drawing function RedrawOneStruct().
* Change context menu text "Noconn" to "No Connect".
* Change context menu text "GLabel" to "Global Label".
* 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
jean-pierre charras
Dick Hollenbeck