Update mhash to the most recent version - 0.9.2
* mhash.3 does not come with the archive anymore so we need to build it
outselves. For that reason pod2man must be used and we add perl build
dependency to the port.
* add patch for doc/Makefile.in to make it work with natural bsd make -
$< evaluates to empty string with bsd make instead of expected
mhash.pod (or whatever).
I'll take it.
Hm, the real maintainer of this port is roam, over to him.