* Remove base screen methods from draw frame object and correct current
screen methods in derived objects.
* Move restore old wires function code into schematic screen object.
* Make add junction method use current screen position instead of store
position.
* Move poly line ghosting function into the delete current segment method
as that was the only place is was being used.
* Add method to base schematic object of testing if object has a label
that can be incremented.
* Simplified the schematic hierarchy traversing code.
* PCBNew Doxygen warning fixes.