This commit replace as much as possible of clean_param and PARAM_ usages related to user object.
Also few unit tests has been changed to match the new validation
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