* Move undo item copy global variable into schematic editor frame object
member variable.
* Add helper methods for accessing the undo item copy member variable.
* Fix undetected bug when changing a text type.
* Added an exchange command to the undo/redo base class for handling undoing
a changed item type which cannot be undone by swapping out the variables.
* Revert change to common/hotkeys_basic.cpp that broke hot key behavior.
* Lots of coding policy changes while making the changes above.
* Change all code references to pin sheet and sheet label to sheet pin to
more closely match the sheet pin object for improved code readability.
* Change menu and tool bar text from pin sheet to sheet pin for improved
user readability.
* Moved sheet pin place method to sheet pin object source file.
* Move last sheet pin stored state information into schematic frame object.
* Add Doxygen comments for the sheet pin editing methods.
* Move locate function code into schematic screen object.
* Move test for junction needed into schematic screen object.
* Move test for marking connected items into schematic screen object.
* Move delete item function code into schematic screen object.
* Move delete all markers code into schematic screen object.
* Add method for locating multiple items in schematic screen object.
* Fix minor bug in schematic field object hit test declaration.
* Initial encapsulation work on item picker object.
* Remove duplicate doxygen comments from item picker object source file.
* Old control state handling code completely removed in all applications.
* Factor common control state handlers into EDA_DRAW_FRAME.
* Replaced EDA_ITEM test for newness with IsNew() method.
* Factor vertical right toolbar command handlers out of giant edit command
switch statement in EESchema and PCBNew.
* 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.
* 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.
* Complete comment translation for all EESchema source files.
* Complete comment translation for all 3D viewer source files.
* Rename class class_hierarchical_PIN_sheet to SCH_SHEET_PIN.
* Rename class DrawSheetStruct to SCH_SHEET.
* Tool tip capitalization fixes.
* Uncrustify and spell check comments and strings in all modified source
files.
* Component library objects renamed for improved readability.
* Fields now move when selected in library editor.
* Add copy constructor to all library draw and library component objects.
* Added copy constructor to EDA_BaseStruct.
* Delete base screen in WinEDA_DrawFrame destructor to prevent potential memory leak.
* Fixed memory access bug when replacing and adding a component to library.
* Moved library component block manipulation code into component object.
* Removed all of the global variables used by the library editor main window object.
* The usual code cleaning and refactoring.