optimizing, commenting, renaming variables

renaming variables; small optimizations; adding comments, TODOs and
FIXMEs; removing unecessary lock/unlock (#129).
removing TODO, its not a bug.
physics debug view fix (co-existing views in transitions)

Now, we no longer have citrus engine remove the debug view by name but instead it removes itself
when the StarlingPhysicsDebugView wrapper or the SpritePhysicsDebugView wrapper gets removed or disposed by StarlingArt or SpriteArt.

debug views are now in theory treated like any other kinds of view (there is probably room for improvement in their implementation too?) and so two can co-exist correctly on state transition.
Merge pull request #131 from ofabricio/master

optimizing, commenting, renaming variables
Merge pull request #130 from mcapraro/master

Extended the flash.display.MovieClip handling functionality to let users...
content = tmpObj
StarlingArt.as
https://github.com/alamboley/Citrus-Engine/commit/b7edfbd747b44e9972038163af7e569576abc86e
overwrote lines from https://github.com/alamboley/Citrus-Engine/commit/59f8740b3ab4ef46f30725042112de430290e44f
Merge remote-tracking branch 'origin/master'
added a reference
AnimationSequence fromMovieClip
AnimationSequence fromMovieClip
#127
StarlingArt.as
'cleanup' after introducing swf -> AnimationSequence
StarlingArt.as
Adding a getter so devs can get the current level index. This is really helpful if you have several levels based off of the same classes so they cant easily be distinguished other than by index