Separate out and export installDirsOptions
Separate out and export installDirsOptions

The InstallDirs is a separate type so it's handy to have the
command line and config file options for it available
separately. It'd be useful in cabal-install for one thing.

20080826003240-adfee-279adc5ed95397999d2413061adc7aa63f32d19a.gz

dcreager/cabal,dcreager/cabal