added Database-Quota dashlet

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

Falko Timme authored Jan 09, 2015 and Patrick Anders committed Jan 09, 2015

- Made sure SQL backups from servers that differ from the server where the website is on can be restored. A download of the backup is not possible in such a case, therefore I hide the "Download" button.

Conflicts:
	interface/lib/classes/plugin_backuplist.inc.php

- Included new icons and buttons
- Layout scaling improved (up to 1260px width)

- New dashboard layout

Removed possibility of reinstalling Instances

- Directive snippets can now be made available to clients; clients can select an available directive snippet for a website - the appropriate snippet will then be written to the vhost configuration file. This is useful for example on nginx where clients have no access to the Options tab of a website.

- Changed tform_actions.inc.php to always provide oldDataRecord array for updates even when dbhistory = off.

Use dovecot or maildrop in default-cases
Switching to LMTP and back included in server-postfix-plugin
validator added to disable switching uid-mapping when already created mailusers or in multiserver-environment