EZS-26 - Implement redirection after a user finishes editing the content in the Content Edit form

https://jira.ez.no/browse/EZS-26

**Implemented:**
* [x] Custom redirection on publish action,
* [x] Custom redirection on close action,
* [x] Custom redirection on discard action,
* [x] Method to set next view service params when switching active view services.
* [x] JS unit tests
Nitpick: instead of manually firing the change event, you could rather update the attribute with `_set` (it's one of the rare case where calling a protected method is acceptable)