Finally my first XF2 AddOn gets an update. 
And now it does more than collapsing, so I rename it to 
Admin Tools.
I got rid of own JavaScript and rebuild all to use XF internal functions.
For Update just do the normal Update process and afterwards you can safely delete the 
js/cv6/collapse folder.
New:
- Added new collapsable areas: Widgets and AddOns. Both can be activated inside the options.
 
- Added am Icon in the Template Modification List to identify fast which type is used. Text, RegExp or PHP.