Remove User Preferences

Authored by Hwboehm on Feb 15 2019, 1:52 PM.


Remove User Preferences

Warning on leaving an edit page was removed, this functionality
is handled by visualeditor.
Removed autosaving artifacts and more obsolete functionality.

Left only code behind which is needed for concurrent edit warnings.

Needs more refactoring, as functionality of edit warnings is now the
only function of this extension, and this warning is still not shown
in visual editor.

ERM #10122

Change-Id: Iaac45c371de110cdeb004e72583425526864c357