Log message:
since perl is now built with threads on most platforms, the perl archlib
module directory has changed (eg. "darwin-2level" vs.
"darwin-thread-multi-2level").

binary packages of perl modules need to be distinguishable between
being built against threaded perl and unthreaded perl, so bump the
PKGREVISION of all perl module packages and introduce
BUILDLINK_RECOMMENDED for perl as perl>=5.8.5nb5 so the correct
dependencies are registered and the binary packages are distinct.

addresses PR pkg/28619 from H. Todd Fujinaka.

Log message:
Import p5-MIME-Types from pkgsrc-wip.  Packaged by Adrian Portelli,
and slightly modified by me.

A start for a more detailed data-structure to keep knowledge about
various data types are defined by MIME.  Some basic treatments with
mime types are implemented.