added methods that were in cc2d-x.
Pulled down update to MonoGame
parity updates to the audio engine to match cc2dx
Merge branch 'master' of https://github.com/Cocos2DXNA/cocos2d-xna

Conflicts:
	cocos2d/denshion/CCSimpleAudioEngine.cs
remove unused definitions
added missing song assets
Merge branch 'master' of https://github.com/Cocos2DXNA/cocos2d-xna
Merge pull request #360 from gena-m/master

remove unused definitions
force the non-use of the MSBuild engine per https://bugzilla.xamarin.com/show_bug.cgi?id=14539 so that MonoMac build will continue to work properly on recently updated Xamarin Studio.
Merge branch 'master' of https://github.com/Cocos2DXNA/cocos2d-xna
fixed concurrent mod that could result in a null timer
helper method to scale a sprite according to a size.
another instance of a NPE in the scheduler during a multi-threaded async load.
Added ability to create a sprite sheet from a list of frames.
Pulled down update to MonoGame
fix for windows 8 build missing a test file.
added an action way of handling tween operations.
added auto-alias generation to the sprite frame lookup
fixed lock around file i/o operation that did not need to be locked. this removes a potential deadlock on android where i/o is considerably slower to physical storage.
Pulled down update to MonoGame