Add delete card template functionality to new card editor and unexposed code for adding

This adds the feature to the new `CardTemplateEditor` to remove card templates, and also add a new template which is the reverse of "Card 1" -- but only when there is only 1 card, and it doesn't have the same name as one of the standard models. Editing of the card templates themselves is disabled as it would be take quite a bit of work to make it usable on a mobile device IMO.

![device-2014-11-15-190206](https://cloud.githubusercontent.com/assets/2818274/5057284/ff5f26f6-6cf9-11e4-812d-1db4a097ced8.png)