added concept of trigger tiles
Merge branch 'dd_cb_triggertiles' into dd_fb_freeze

Conflicts:
	src/game/gamecore.cpp
	src/game/mapitems.h
fixed memory leak and merged enums
Merge branch 'dd_cb_triggertiles' into dd_fb_freeze

Conflicts:
	src/game/collision.h
fixed flag names
removed flag concept
Merge branch 'dd_cb_triggertiles' into dd_fb_freeze

Conflicts:
	src/game/collision.cpp
	src/game/collision.h