GridView attempt 2
Change the dialogue screen to work with the new DialogueView
Use listenTo() instead of on() for listening for grid reorder events in DialogueStateCollection
Fix dialogue state drag disabling for connected states (the current workaround for the jquery ui sortable bug does not work with the new GridView)
Refactor grid parts of dialogue state collection into DialogueStateGridView
Fix dialogue state titlebar input selection (wasn't working with jquery ui sortable's cancel option)
GridView.p.add and .clear should return 'this'
Merge branch 'develop-frontend' into feature/issue-472-gridview-needs-to-make-appending-individual-items-easier