View controller: Recognize pan gestures on a view level
View controller: Recognize pan gestures on a view level

This change moves the gesture recognizer used for pan (scroll) events in
the collection view to the view level. This is done in order to support
scrolling on a header or overlay component, without having to resort to
manual -pointInside checks. 
spotify/HubFramework,spotify/HubFramework,spotify/HubFramework,spotify/HubFramework