ui tweaks; persist the theme setting between sessions

Some small UI tweaks to the toolbar area, and persist the ace theme setting between sessions.

![screen shot 2013-10-24 at 1 42 01 pm](https://f.cloud.github.com/assets/1269969/1402997/c8490120-3cec-11e3-88c8-1ee85af4981a.png)

@keertip @dinhviethoa