fixed frame's value not right when enter a frame
add timeline test
fixed crash when change test
add timeline frame event test
Merge pull request #7111 from 2youyouo2/v2

add test and fixed some bugs
fix layout opacity
Merge pull request #7114 from andyque/fixBinaryLoadingV2

fix layout opacity
Merge branch 'v2_test' of https://github.com/samuele3hu/cocos2d-x; branch 'v2' of https://github.com/cocos2d/cocos2d-x into v2_test