better defaults, create missing directory
dkim for centos
centos uses opendkim user which is arguably better
Merge pull request #206 from phunehehe/dkim

dkim for centos
Merge pull request #205 from phunehehe/icinga

better defaults, create missing directory
give sftp users proper homes
Merge pull request #207 from phunehehe/sftp

give sftp users proper homes
Merge pull request #204 from phunehehe/roundcube

use release branch instead of tag
include apc when needed