devel/hs-terminfo: Integrate from Ports Collection
lang/ghc: Move Cabal directories out from the GHC ones

This helps to avoid overlapping between packaged directories and be more
friendly with solutions like the combination of portmaster(8) and
pkg(8).

Reported by:	sperber, bapt
Discussed with:	ashish
Update contents.  (Reported by: Armin Pirkovitsch (sperber@))
Simplify contents a bit.
Further simplification and fix a bug.