FlxSpriteUtil: removed some unnecessary null checks
Remove race condition when opening/closing substates in same update
Merge pull request #1219 from JoeCreates/dev

Remove race condition when opening/closing substates in same update
Add unit test for #1219
Update CHANGELOG.md
FlxSprite: use FlxRect for clipRect() and add setFramesData() for less redundancy
Fix FlxVector#radiansBetween() / degreesBetween()
FlxGame#resizeGame(): resize the _displayBitmap on HTML5, closes #1216
Some cleanup for the unit tests (got rid of TestUtil)
FlxPath: fixed potential null errors in restart() and destroy()
Get rid of async unit tests by simulating Lib.getTimer() and using FlxG.game.step()
FlxPath: fixed an issue where a velocity would be set even if the object positon matches the current node

+ some cleanup
Minor cleanup
FlxCamera#bgColor: slightly less confusing docs

Could be interpreted as transparent camera backgrounds not working on non-flash targets.
Merge remote-tracking branch 'upstream/dev' into dev
Add a global CachedGraphics persistence variable.

If specified, CachedGraphics will use the persist value supplied by the
constructor. Otherwise, it defaults to the value of
persistentCachedGraphics in FlxG.

This allows globally setting what the persist value should default to,
making it easier to keep desired assets persistent between state
changes.