Adds range limit plugin

Fixes #218 

Adds range limit plugin for facet page and advanced search. Resolves advanced search integration tests with dates.

![screen shot 2014-06-23 at 3 29 39 pm](https://cloud.githubusercontent.com/assets/1656824/3364941/f3dd32f0-fb25-11e3-8a7d-7d547067e3db.png)

![screen shot 2014-06-23 at 3 29 59 pm](https://cloud.githubusercontent.com/assets/1656824/3364943/f791fcd2-fb25-11e3-8c33-e7fb30ba2d1c.png)


Are these form field intended to go after the facets (and not be grouped w/ the other fields)? Just seems a little odd to me.