This commit coverts everything in the codebase to use the new
users_order_by_sql function when sorting lists of users. More details in
the bug.
Note that this does not change places where users are displayed in a
sortable table, and the sort order comes from the table.
Included is a bug correction to categories_delete_move() which does not
respect showfeedback parameter, printing feedback even when not wanted
(this breaks the webservice output)
Conflicts:
admin/webservice/testclient_forms.php
lib/db/services.php