Add mandir support to InstallDirs
Add mandir support to InstallDirs

It's not used by Cabal at all but some packages want to install man pages
and this should make it easier for them to figure out where to install them.
In particular c2hs and lhs2tex have man pages.

20071207141839-adfee-486166db76ded9deebaac8d98e4694aab2441a65.gz

dcreager/cabal,dcreager/cabal