Merge branch 'dns-additions' into 'stable-3.1'

install/sql/incremental/upd_dev_collection.sql

install/sql/ispconfig3.sql

interface/lib/classes/remote.d/dns.inc.php

interface/web/dns/dns_cname_edit.php

interface/web/dns/dns_dname_edit.php

interface/web/dns/dns_sshfp_edit.php

interface/web/dns/form/dns_dname.tform.php

interface/web/dns/form/dns_sshfp.tform.php

interface/web/dns/lib/lang/ar_dns_a.lng

interface/web/dns/lib/lang/ar_dns_aaaa.lng

interface/web/dns/lib/lang/ar_dns_cname.lng

interface/web/dns/lib/lang/ar_dns_dname.lng

interface/web/dns/lib/lang/ar_dns_sshfp.lng

interface/web/dns/lib/lang/bg_dns_a.lng

interface/web/dns/lib/lang/bg_dns_aaaa.lng

interface/web/dns/lib/lang/bg_dns_cname.lng

interface/web/dns/lib/lang/bg_dns_dname.lng

interface/web/dns/lib/lang/bg_dns_sshfp.lng

interface/web/dns/lib/lang/br_dns_a.lng

interface/web/dns/lib/lang/br_dns_aaaa.lng