Extension for support 5 animation tools

Extensions
#1

I migrated some code to support five animation tools, they are: Motion Welder, Arctic, AuroraGT, SpriteX, SpriteX 2011.
repo is here: https://github.com/stubma/cocos2dx-anim
demo included for ios and android.

One known-issue is related to cocos2d-x bug, look readme carefully. Enjoy.

#2

Great!Are you the author of WiEngine？
A few month ago,I also migrated code to support AuroraGT animation tools from WiEngine.My code works,but some features are not completed.