#219 handle uncommon _dmarc records in a RFC 7489 comformant way

[A. Schulze]

_dmarc.$domain is expected to start with "v=DMARC1" followed by "p=$policy"

opendmarc don't check this but exept a DMARC record "off-v=DMARC1; p=..."
tha attached patch show a possible implementation of such checks. It's not intended as solution but only poke some syslog while calling "opendmarc-check"

[A. Schulze]

example domain: endutec.de