deposit: import button fix feedback

Signed-off-by: Javier Martin Montull <javier.martin.montull@cern.ch>
deposit: task management refactor

* Simplifies code related to multiple tasks and deferred objects.

Signed-off-by: Javier Martin Montull <javier.martin.montull@cern.ch>
deposit: import message improvement

Signed-off-by: Javier Martin Montull <javier.martin.montull@cern.ch>
deposit: collapse show state with Chevron icons

Signed-off-by: Georgios Kokosioulis <georgios.kokosioulis@cern.ch>
deposit: change of hiding method of hidden fields

* Uses HiddenInput widget in forms.py, and hides
  all leftovers generic using class based jQuery
  selector in fillform.js.

Signed-off-by: Kamil Neczaj <kamil.neczaj@cern.ch>
deposit: quite nicely working typeahead for conferences

Signed-off-by: Kamil Neczaj <kamil.neczaj@cern.ch>
base/deposit: conferences typeahead as jquery plugin

Signed-off-by: Kamil Neczaj <kamil.neczaj@cern.ch>
deposit: proper submision for conference

* Adds conference_id hidden field to forms.py.

Signed-off-by: Kamil Neczaj <kamil.neczaj@cern.ch>
deposit: new and big mock

Signed-off-by: Kamil Neczaj <kamil.neczaj@cern.ch>
deposit: check type on tokenization

Signed-off-by: Kamil Neczaj <kamil.neczaj@cern.ch>