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.
The forms ( as symfony form components) are different, one is a list of checkboxes the other one is a simple hidden box. We could tweak the code to make it work, but I think it is a lot more simple like that. I can do it if the majority is for it.