Fixed retina/contentScale position errors for iPhone 6+ devices in EditBox.

Problem is that factor was 1.0 or 2.0 until iOS 8 introduced 3.0.
Merge pull request #1 from cocos2d/v3

Update from cocos2d-x
Merge branch 'v3' of https://github.com/cocos2d/cocos2d-x into v3
Merge branch 'v3' of https://github.com/cocos2d/cocos2d-x into v3
Merge branch 'v3' of https://github.com/cocos2d/cocos2d-x into v3
let billboard can rotate in the Z axis
Remove useless copy about luasocket on the android platform
Merge pull request #9388 from cocoscodeide/v3

update runtime version to 1.6
update for cocos reader
ListViewReader completed and listview callback feature.
update for cocos reader
update ReleaseNotes
update ReleaseNots
update ReleaseNotes
Merge pull request #9392 from dabingnn/v3_releaseNotes

V3 release notes
fixed renameFile for wp8 and winrt to pass file and assetmangers tests
invoke closedir after invoke opendir
calculate aabb if not exist
Merge pull request #171 from tangziwen/v3

let billboard can rotate in the Z axis
closedir when succeed