update SB+SK module
fix button background opacity sometimes not applied
timeline: hide easing modes not in Sprite Kit
SB+SK updated
added SK file node, fix ccb dragging creating CCFile node
pbxproj update with new SKFile node plugin
sb+sk submodule update
Merge branch 'develop' of github.com:apportable/SpriteBuilder into develop-steffen
sb+sk submodule
update description of "Sub File" node
SB+SK submodule with CCBReader integrated
sb+sk submodule
update Sprite Kit default project, fix errors/warnings
update SB+SK submodule
Merge pull request #344 from KoboldKit/develop-steffen

various bugfixes, added "Sub File" node type