updating RBSplitView
Merge branch 'master' of https://github.com/typemytype/vanilla

Conflicts:
	Lib/vanilla/externalFrameworks/RBSplitView/RBSplitView.framework/Versions/A/Headers/RBSplitSubview.h
	Lib/vanilla/externalFrameworks/RBSplitView/RBSplitView.framework/Versions/A/Headers/RBSplitView.h
	Lib/vanilla/externalFrameworks/RBSplitView/RBSplitView.framework/Versions/A/RBSplitView
	Lib/vanilla/externalFrameworks/RBSplitView/RBSplitView.framework/Versions/A/Resources/Info.plist