Axmol engine support

[rh101]

Axmol Engine is a fork of Cocos2d-x v4, but it has diverged from its origins enough that anything written for Cocos2d-x would need to be modified to work with Axmol.

I've successfully managed to get the GAFLibrary working with Axmol v2 in this fork of the GAFPlayer repo, and so far there are no issues. I don't understand enough about GAFPlayer or the internal format to be effective at maintaining that library, so if you wish to add that work to your repository then that would be great.

The example and test projects have also been updated to work with Axmol v2.