[TopDown] Added a config to allow top-down games more easily.
[TopDown] Added optional vertical sprite flipping
[TopDown] Altered updateAnimations of Character abstractity to move properly with top_down enabled.
Merge branch 'up-dev' into F-top_down

Conflicts:
	lib/plusplus/abstractities/character.js
[TopDown] Refactored configs to TOP_DOWN and FLIP_Y. Fixed bug in lookAt method.
[TopDown] Rewrote lookAt functionality for top_down games.
[TopDown] Added example, fixed animation pausing for character abstractity.
[TopDown Example] Fixed offsets passed to Shoot ability to work in all four directions.
Merge branch 'up-dev' into F-top_down

Conflicts:
	lib/plusplus/core/entity.js
Reverted accidental modification.
Merge pull request #31 from bdaenen/F-top_down

F top down