* Add item clarification context menu to EESchema when multiple unresolved
items are found at the current cross hair position.
* Add collector class SCH_COLLECTOR for supporting multiple item hit testing.
* Removed bit wise masked filtering from schematic item hit testing.
* Removed all old hit testing functions and methods scattered about the
EESchema source code.
* Move terminal point test function into SCH_SCREEN object.
* Fixed bug in terminal point test when terminating a bus to a label.
* Define the < operator for sorting schematic items.
* Add area calculation method to EDA_Rect item.
* Add method for returning an item's bitmap for menu display purposes.
* Add method for returning an item's menu text for menu display purposes.
* Changed EDA_ITEMS container from boost::ptr_vector to std::vector.
* Factor coordinate string conversion code from EDA_DRAW_FRAME to function
CoordinateToString().
* 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.