Merge master branch to develop branch
Merge branch 'develop' into develop_nutty_Mergemasterbranchtodevelopbranch

Conflicts:
	cocos/gui/UIHelper.h
temp commit
Modify mk files
Merge branch 'develop' into develop_nutty_Mergemasterbranchtodevelopbranch
Test commit
fixed linux build error
Merge branch 'develop' into develop_nutty_Mergemasterbranchtodevelopbranch
Merge pull request #4113 from nutty898/develop_nutty_Mergemasterbranchtodevelopbranch

Merge 2.x version to 3.0 version