corrected representation of datetime filter
changed the data-date-format for datetime filters in form.js
changed bootstrap3 datetime filters to be compatible in same way as issue #603
changed data-date-format for datetime bootstrap3 filters. Solves same issue as #603 for date fields
Merge pull request #621 from boombard/master

Fix for datetimepicker fields in filters for bootstrap3. Extends the fix for datepickers from issue #603.