Bugfix: Shadows overlapping/glow in stroke.
Merge pull request #679 from NickyWeber/bugfix/cclabelttf_shadow_overlap_strokessue

Bugfix: Shadows overlapping/glow in stroke.
Minor CCClippingNode and transition fixes.
Adding renderer tests for CCClippingNode.
Merge branch 'v3.0' into develop

Conflicts:
	cocos2d-ui-tests/tests/CCRendererTest.m
	cocos2d/CCClippingNode.m
	cocos2d/CCTransition.m
Fixed an issue with gradient vertex colors.
CCClippingNode implemented.
Mac Fix for stenciled transitions.
Merge branch 'v3.0' into develop
ClippingNode fixes.
Enable depth+stencil on Mac