Add AttitudePlus support to Multi-rotor airframes.

1) Adds AttitudePlus to multirotor. 
2) Changes layout so that the trim button is in a standard place on all pages.
![screen shot 2013-09-11 at 12 01 27 pm](https://f.cloud.github.com/assets/1118185/1121765/33403232-1ac9-11e3-8b24-688ebf71697f.png)

As always, I'm happy to hear suggestions on where new buttons can live.