Merge pull request #8714 from owncloud/minor-fixes

fix some minor issues
access admin settings result message correctly
move mail template editor from core to standalone templateeditor repo
Merge pull request #9010 from owncloud/fix_8941_admin_settings_message

move mail template settings to templateeditor repo
fix mail settings save function - ref #8854
Basics
Use appframework
Changes according to review
Change routes. Update templates
Remove debug output
Fix check for user existence
Add missing use
use more stuff from core :)
more style fixes
reformat method call and fix paranthesis mismatch
Remove infield label, add password icon, fix layout
Migrate ´ to '
remove whitespace at end of line
complete renaming uid to userId
use array_merge for merging arrays in PHP