Fix typos
Fix macro path issue
Add nullify method to Matrix class
Add method to check if console mode is on/off
Edge collapse method
Fix possible crash when checking for available undo/redo
0001189: Re-assign hot keys 0 thru 6 to line up with the icon placement.
Arch: Restored length property of walls

Walls can again be based on no underlying object, and be
only defined by length, width and height.