Moved global definition out of config and into index.php
Web-service notifications now happen asynchronously via cron.
Merge branch 'Notification_queue'
Double requests to remove a user now only require a second "OK".

It seems that when adding two users to a group and then removing the two
users, the second user will cause something like two button-press events.
The first one will properly remove the user, but the second one will fail
since the user is already removed from the group.

Now, if the user is already removed, a special 506 status code is returned
which the Javascript interprets as "User is already out of the group" and
hides the user element from display.
Unbinding click-event listening from the remove button when we begin removal.

For some reason two click events were firing for member removal. This change
tells the element to stop listening for click events so that the removal only
happens once.
Cleaning up the DOM after member removal.