DKIM: changed config-file-check to prevent saving the keys in the wrong file if a single amavis-config-file exists after upgrading to a "split-config"

- upd: better error handling and logging

Fix for mailrestore, to avoid confusion about web- and mail-backups with same ids

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

see:
- http://git.ispconfig.org/panders/ispconfig3/commit/f7ec00b2f8ba3efc5bdeacef9c813f8a826ae3be#note_455

- http://en.wikipedia.org/wiki/SPDY

- 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.

Fixed a Bug in Centos 7 were php-fpm uses sockets while mod_proxy_fcgi in centos 7 does not support that yet.

- Fixed: FS#3710 - Bug with PHP-FPM configuration since 3.0.5.4 Patch 4
- Fixed wrong function calls in system lib.

-Added a new option "Network Filesystem" under System > Server config > Web to toggle on / off the _netdev option for the bind mounts in /etc/fstab

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

Note: The mod_proxy_fcgi that ships with CentOS and Ubuntu does not support sockets yet, so all php-fpm connections are done by IP.