* Allow user-defined PMs (in case they have custom scripts, etc.)

* Have the option to spit out the PM command to be used instead of using it.

* Pretty colours in output?

* Detect packages that are installed but not registered with GHC.
  This is for cases where GHC was re-built but packages were not
  properly re-registered.

* Add an --info option to give us information on haskell-packages, etc.