utils: `TextField` replacement by `StringField`

* Replaces the usage of `TextField` by `StringField` as it will be
  deprecated in wtforms 2.0.

* Fixes the `super` call.

* Removes trailing spaces (PEP8).

Signed-off-by: Yoan Blanc <yoan.blanc@cern.ch>
Reviewed-by: Jiri Kuncar <jiri.kuncar@cern.ch>
search: label `for` attribute addition

* Adds the `for` attribute on the labels of the advanced search.

Signed-off-by: Yoan Blanc <yoan.blanc@cern.ch>
Reviewed-by: Jiri Kuncar <jiri.kuncar@cern.ch>
grunt: jquery plugins additions

* Adds missing `datepicker.css`, `theme.css` and
  `ui-bg_flat_75_ffffff_40x100.png`.

Signed-off-by: Pedro Gaudêncio <pedro.gaudencio@cern.ch>
Reviewed-by: Javier Martin Montull <javier.martin.montull@cern.ch>
communities: broken url fix

* Fixes a broken URL in the community edit page.

Signed-off-by: Lars Holm Nielsen <lars.holm.nielsen@cern.ch>
utils: datacite tester fix

* Fixes test case for DataCite API interface.

Signed-off-by: Lars Holm Nielsen <lars.holm.nielsen@cern.ch>
communities: curation button fixes

* Fixes display of error message reporting.

* Fixes icons in accept/reject buttons.

Signed-off-by: Lars Holm Nielsen <lars.holm.nielsen@cern.ch>
formatter: format template path fix

* Fixes path used to load format templates. Previous path
  assumed all templates where located in Invenio.

Signed-off-by: Lars Holm Nielsen <lars.holm.nielsen@cern.ch>