- When showing vulnerability warning give an explanation that there

will not necessarily be an update. Give advice on how to skip the
  check. It is the user's choice afterall.

With hat:	portmgr
Reported by:	jhb

Mk/bsd.port.mk

@@ -3325,6 +3325,8 @@ check-vulnerable:
 			${ECHO_MSG} "===>  ${PKGNAME} has known vulnerabilities:"; \
 			${ECHO_MSG} "$$vlist"; \
 			${ECHO_MSG} "=> Please update your ports tree and try again."; \
+			${ECHO_MSG} "=> Ports are marked vulnerable regardless of their being an update available."; \
+			${ECHO_MSG} "=> If you wish to ignore this vulnerability rebuild with 'make DISABLE_VULNERABILITIES=yes'"; \
 			exit 1; \
 		fi; \
 	fi