EZP-23678: Add edit and remove on view section

Link: https://jira.ez.no/browse/EZP-23678

## Description
See issue.

## Screenshot
Buttons need some positionning.

![sectionview](https://cloud.githubusercontent.com/assets/4035241/5284534/2f0c06e8-7b15-11e4-96d0-f4b9d41605dc.png)


## Test
Manual

## TODO
- [ ] Position buttons in the page
- [x] Create a formtype
- [x] Sanity tests
- [x] Update display rules on delete button --> follow up story, depend on kernel future dev.
can't we use the same controller/action in both cases? From an external perspective, deleting one section is "just" a special case in deleting several, no ?