Attempt to fix this port, which seems to break every time ImageMagick is
updated by switching it to use GraphicsMagick instead.
This removes the need for "private" headers and promises a less eventful
Don't install mimetype-descriptions, which conflict with those installed
by kdelibs and otherwise improve plist. Build in parallel using our own
make (no evident need for gmake).
The port may be retired soon, as no new development happened on it since
Approved by: portmgr (linimon)