Fixed #4057 Remote API: some API calls are not working because the form definition files are missing

Posibility to change main-domain of aps-instance over remote (in interface maindomain is always the websites domain but over remote it's now possible to set an alias oder subdomain, that will be used in instance-settings. Important if e.g. wordpress-installation should run unter an aliasdomain instead of the websites domain)

Conflicts:
	interface/lib/classes/remoting.inc.php
	interface/web/mail/templates/mail_user_backup_list.htm
	interface/web/sites/lib/lang/en_web_backup_list.lng
	interface/web/sites/lib/lang/es_web_backup_list.lng
	interface/web/sites/lib/lang/tr_web_backup_list.lng
	server/plugins-available/backup_plugin.inc.php

added possibility to change package-status over remote

added Database-Quota dashlet

Fixed error in Mail-Backup-Cron-Task (created file /dev/nul - missing l)

Removed possibility of reinstalling Instances

Improved API behaviour: The $params array must contain only the new values and not all values of a record on update. Setting all values does not hurt though, so the change is downwards compatible with older versions.