Update closure compiler to the latest for feature issue #1651
Fix rounding errors on ease actions

When update(t) and t==1 or t==0, then the inner function should receive
t=1 or t=0
Merge pull request #798 from ayuer/master

Update Google Closure to latest version
Merge pull request #801 from ricardoquesada/ease_rounding_error_fix

Fix rounding errors on ease actions
Merge branch 'master' of git://github.com/cocos2d/cocos2d-html5
wrap up the canvas's context in CCDrawingPrimitive.js

the cc.CanvasCtxWrapper is the placeholder, most codes are still in
test.html
Currently, it works perfectly in chrome, good but not perfect in safari,
throwing exceptions in firefox & ie...