Updated TODO.
Merge branch 'cutting-edge' into refactoring/mapclean

Conflicts:
	documentation/TODO.md
First shot at replacing map clean :)
Items on tiles will expire after 10 minutes.
Merge branch 'cutting-edge' into refactoring/mapclean
Removed TRAP signal from documentation.
Merge branch 'cutting-edge' into refactoring/mapclean
Removed TRAP signal handler registration.
Fixed bug in creature movement firewall.
Merge branch 'refactoring/mapclean' into cutting-edge