* 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.