Bugfix for #664, relase publish and smartsheets generate optpng errors.
Merge branch 'v1.1' into bugfix/1.1/#664_release_publish_optipng

Conflicts:
	SpriteBuilder/ccBuilder/CCBPublisher.m
	SpriteBuilder/ccBuilder/PublishImageOperation.m
Merge pull request #665 from NickyWeber/bugfix/1.1/#664_release_publish_optipng

Bugfix/1.1/#664 release publish optipng