U4-5520: Localize date/time picker (2nd try)

This is an update of #504, due to serious issues discovered with this PR.
This PR addresses these issues as follows:

**Value is not saved**
This has been addressed by updating the datepicker Angular controller to use the new events from the datepicker

**event names changed from old datepicker**
Events with the old names have been added by modifying the library (clearly marked with comments). The events in question are `changeDate`, `show` and `hide`. The parameters for `changeDate` also have the same incorrect values as the previous datepicker

**PR #498**
The datepicker hides correctly when clicking outside it

**PR #491**
The datepicker closes, when a date is selected. The datepicker with time does not, as you need to select a time as well.