Openvpn: Change sortorder of client status and control

Now every NET is sorted and second instance is the NAME of the VPN.
OpenVPN: change sortorder of client status and control. Now every network is sorted and displayed in a group
netexternal.cgi: Show DNSSEC status

The netexternal.cgi has been extended to show what type
of DNSSEC support the upstream nameservers offer.
Merge remote-tracking branch 'amarx/openvpn'
ddns.cgi: Add handling for entrydns and opendns.
Merge remote-tracking branch 'stevee/ddns-new-providers'