Fix for jQuery 1.8's changes to .then()
Fix for jQuery 1.8's changes to .then()

SimenB/backbone.layoutmanager,tbranyen/backbone.layoutmanager,tbranyen/backbone.layoutmanager,huang-x-h/backbone.layoutmanager,SimenB/backbone.layoutmanager,GerHobbelt/backbone.layoutmanager,huang-x-h/backbone.layoutmanager