Add file field to article bundle

Fixes EDOZWO-365, please run update script.
Fix triggering element in AJAX form submit.

Fixes EDOZWO-363
Clear cache on entity save

Fixes EDOZWO-364
Don't clear cache on insert

Fixes EDOZWO-368
Add jquery.ui.datepicker.js

Fixes EDOZWO-371
Fix data import when editing existing resource

Fixes EDOZWO-370
Merge pull request #23 from literarymachine/0.5

0.5 bugfixes