Log Message:
Allow "inet6" as a package option for net/couriertcpd and
mail/courier-mta.  Modify mail/courier-imap to build regardless of
the platforms IPv6 support and update meta-pkg/courier to the latest
versions of the Courier mail server suite.  Bump the PKGREVISIONs
of the following packages:

	mail/courier-mta	--> 7
	meta-pkgs/courier	--> 3
	net/couriertcpd		--> 2

This fixes PR pkg/37013 by Aleksej Saushev.