[TASK] Improve feedit

The frontend editing + admin panel needs some polishing.
Following changes are included:

General
=======
- Reformat code
- Use Sprite API which means using the correct icons

Admin Panel
==============
- Add missing translations
- Show "Simulate usergroup" only if usergroups are available
- Remove "Total page count" in Info Tab as information is wrong
  (counting images + document is not the total page size)

Frontend Editing
=================
- Remove "edit_editNoPopup", "forceNoPopup", "editFormsOnPage"
  for direct inline editing
- Remove setting "previewBorder" which is not needed and looks just ugly

Releases: 6.2
Resolves: #49640
Change-Id: I35f88bc4e8c138fc21b74c0448b2f3892ab61918
Reviewed-on: https://review.typo3.org/21859
Reviewed-by: Markus Klein
Tested-by: Markus Klein
Reviewed-by: Wouter Wolters
Tested-by: Wouter Wolters