[Task]: CGL and code clean up
[TASK] removing loadTCA call
Task #51952: removing t3lib, remove global
Task #51952: seperation classes from index.php
Task #51952: namespace and folder structure
Task #51952: fix edit form
Task #51953: added switch-to button for User admin view and overview
Task #51953: added flag to allow user to use the switch-to button
rename to Controller
Task #51955: duplicate the perm module, so non-admin user can use this
Task: convert document to ReST format
Task #51953: check switch-to icon.
Task: use default BE template
Fix: wrong class namespace
Task: added documentation to new checkbox
fix docu
set version to 2.0 and dependency to 6.2.x
Task #52739: fix double html header
Task #52739: fix double html header
Task #52744: added TSConfig to hide fields in user or group edit form.