started working on line brush
Merge branch 'master' of https://github.com/jensenr30/GridSim into gui2
started working on resisable brushes
started working on circle brush
Merging master with gui2. There shouldn't be any bugs.

Conflicts:
	GridSim.cbp
	selection_gui.h
Merge branch 'master' into gridwork

Conflicts:
	cell_engine.h
^ re-mapped the panning to the Alt+mouse_motion