succint button copy + force single line grouped buttons

This is a fix for #359 that forces text on to a single line. I also shortened the text for returning to inbox/outbox. The 'mark as i have never..." is just a temporary edit to show the single line + ellipsis effect.

Here is what happens now when you have very long button titles:
![screen shot 2013-07-29 at 7 48 00 pm](https://f.cloud.github.com/assets/108094/875681/51adaeda-f8a9-11e2-8385-b10c1bc12726.png)