Fix very short filter input in Firefox

* Rearrange order of wrappers, placing label in grid cell too and
removing form-group wrapper
* Convert filter from input to button for correct height, it seems
bootstrap 3 doesn’t like input type submit much,
http://stackoverflow.com/questions/18542343/is-there-a-way-a-aligning-my
-input-group-on-firefox-using-bootstrap-3