Update comparisons when an adjustable rate is selected

This is the first pass at updating this. The warning displays instantly, but the length of the loan and calculations don't update until the data is returned. This feels a little clunky and weird and probably needs a little UX love.

![screen shot 2014-06-13 at 4 17 18 pm](https://cloud.githubusercontent.com/assets/212533/3275149/4008bea6-f338-11e3-92f9-09823559e108.png)