Merge pull request #3303 from minggo/develop

set _isDownloading to false before return
Merge pull request #3304 from minggo/develop

fix a logical error
Modify  deprecated CCPhysicsDebugNode typedef and some test bug
Merge branch 'develop' of https://github.com/cocos2d/cocos2d-x into DrawNode
Merge pull request #3305 from samuele3hu/DrawNode

Modify deprecated CCPhysicsDebugNode typedef and some test bug
fixed warnings on Android and windows