Fix cc.view._resizeWithBrowserSize typo (cocos#3130)

Fix return type should be vec2 instead of simple object for fireball/…

…issues/7898 (cocos#3046)

Improve doc for Node zIndex

fix the loadResDir function param transfer problem (cocos#2992)

fix loadResDir completeCallback absent issue

Merge branch 'v1.9'

update version to 1.6.0