GridView can draw custom group headers.
Fix #1416.
Fix header text shadow and center text vertically.
Rearrange some collection view controller code.
Fix some analyser warnings.
Update OpenEmu-SDK submodule ref
Fix typo and rename OECollectionViewItemProtocol to OEGameCollectionViewItemProtocol
Implement rough version of saved games view.
Update grid_header image.
Test by system sorting for media views.
Forgot xcode project.