Branch off for turning_notifcation overlay testing.

TODO: for testing, try throwing up some sort of overlay that lets you know when you need to make a turning decision; something that shows the directions you can turn right now. that might be enough to improve the feeling of the controls.
Creating a Tilemap class to encapsulate the work we have to do surrounding loading the tilemap and its objects. This can also encapsulate the “collision” paths from authorizeTurnEvent so that we can load those only once instead of drawing them on every call.
Merge branch 'ui_turn_hints'

Conflicts:
	CharacterTests.xcodeproj/project.pbxproj

CharacterTests.xcodeproj/xcuserdata/alextaylor.xcuserdatad/xcdebugger/Br
eakpoints_v2.xcbkptlist