Merge branch 'staging' into 582-disable_editing_on_mirrors
split access to private_r and private_rw
change access select box dynamically

This doesn't work yet because the event handler
function change_options is recognized as undefined
when passing it to .change(handler).

The select box only gets the applicable options
because *_rw is not suitable for a mirrored
repository.
finish select box option handling for mirrors

* remove `window.` to not pollute the global namespace
* fix on-change event handling
* select best fitting option when switching from
  mirrored to non-mirrored and vice versa
Merge branch '582-disable_editing_on_mirrors' into develop