Enable Stencil buffer on Mac.

Enable Stencil buffer on Mac.
Merge pull request #214 from nealzxc/master

Enable Stencil buffer on Mac, for CCClippingNode.
add 2048
add 2048
2048 bug for touch
2048 bug for touch
ples/2048/

license

Signed-off-by: hanxi <hanxi.info@gmail.com>
change redeme for update.lua
Merge pull request #290 from hanxi/develop

add a sample 2048 game for quick-cocos2d-x