Timeline: minor add range bugs

Today, I found two minor bugs of the timeline in edit mode with range items:

1. If you add an item via double click, everything works fine. If you use dragging with ctrl, DataView.filter throws an error because data is null. Example: http://jsfiddle.net/yo5Lppb7/
2. If you set snap: null, dragging with ctrl throws an error, too. Example: http://jsfiddle.net/djjfoyuf/

I don't need them to be fixed. It's just a report.