* 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.