Adds datepickers to documents search filters

* Uses jquery UI since that's already here, and non-terrible.
* Also changes the form to use bootstrap's suggested form <div>s
  because, although not semantic, they make styling a lot easier.
Adds date filtering to documents controller
Document date filter formats date correctly for controller
Document date filter is inclusive
Fixes document date filter selectors to match controller
Removes datepicker init JS

No need as automatically performed on elements with datepicker class
post-rebase fixes
Merge branch 'documents-filter-by-date' into develop