Fixed: FS#3350 - [Dovecot] Warning: mysql: Query failed, retrying: Unknown column 'filter' in 'where clause'

Fixed: FS#3032 - dovecot: master: Warning: /var/www/clients/client20/web36/log is no longer mounted. If this is inten

- Use it like $app->conf('yourpluginname', 'config-key', 'value')
- omit the value to read the config value, provide it to set the value

- Add missing configuration inclusion (vhost files) to apache config

- Added email message templates.

- Added section toggle for client limits

- Add config to clear php handler in apps vhost.

- Added options to use a mounted backup directory. This allows for remote backups, e.g. vis sshfs to a backup server. The backup script checks if the backup directory is mounted, and if not, tries to mount it.