Group division filters

This is a small step forward on the divisions#index. Puts the lead copy forward and groups the list filtering options.

![2014-09-15-divisions-filter copy](https://cloud.githubusercontent.com/assets/1239550/4266266/8596b060-3c79-11e4-99c7-6c62bf39987e.jpg)

@mlandauer this bumped into the work you've been doing on the help routes during merge. I'm pretty sure I've made the correction, all tests passing.

Closes #456