messages: jQuery-Timepicker-Addon fix
messages: jQuery-Timepicker-Addon fix

* FIX Defines a path for jquery.ui required by jQuery-Timepicker-Addon
  and sets an exact version for the plugin instead of latest.
  (closes #2910)

Signed-off-by: Leonardo Rossi <5460ec99b71a72e7693c4088b5c2585e76e1c857@cern.ch>
Reviewed-by: Jiri Kuncar <2bdffcb416fed3002465740d19a053a39918cbe5@cern.ch>

inveniosoftware/invenio-base,tiborsimko/invenio-base,inveniosoftware/invenio-base,tiborsimko/invenio-base