Merge pull request #377 from smfreegard/master

Prevent loop_respond() function from running if disconnecting
Bubble up better errors from Address parser
Strict checks for rfc1869 MAIL/RCPT lines
Merge pull request #380 from baudehlo/strict_rfc1869

Strict checks for rfc1869 MAIL/RCPT lines
Add Haraka systemd service file to contrib