Update CCLuaEngine.cpp

Null pointer check in order to prevent crashes.
Merge pull request #2261 from flaming0/gles20

Null pointer check in order to prevent crashes.
Update AUTHORS
Adding LabelTest.lua. Three tests in LabelTest works ok.
Updating mainMenu.lua
Merge pull request #2265 from dumganhar/master

Adding LabelTest.lua. Three tests in LabelTest works ok.
add oPlatformWorld, oCamera for platform game
Merge remote-tracking branch 'remotes/upstream/master'