Object angle. Hopefully it's the correct thing

[atheros]

Added support for angle in TMX, Lua and JSON plugins
Added support for angle drawing in orthogonal map renderer
Added angle to Object Properties window
Fixed MapObject bounding box (only rect shape and tile object) in orthogonal map renderer to contain the angle arrow.
Added a view option to enable or disable angle arrow
Poly* don't have angle arrows

[bjorn]

I've cherry-picked this onto the wip/rotation branch, and used it as the base for adding object rotation. However, the intention of that branch is to allow objects to be rotated, not to add an angle arrow to them.

[bjorn]

Closing this since the wip/rotation branch is now merged. This commit was cherry-picked as 301ffd6, but the actual drawing of the arrow was removed again in commit 6b0e3e6.

[gamedevsam]

You're on a roll bjorn! Great work!