add a send feedback button

@ussuri, add a `Send Feedback` button to Spark's about box. I experimented with having it in the spark menu, but that menu's getting a bit long - I want to be careful of what goes in there.

Also, changed our template code so that templates that have an `index.html` at the top level - and no other entry point - open that when a new project is created.

![screen shot 2014-05-14 at 1 40 58 pm](https://cloud.githubusercontent.com/assets/1269969/2977266/678a34ce-dba9-11e3-9e1f-3ade86558671.png)