Re-structure support for libraries in GHC:
This commit splits off the supporting libraries that pull in additional
dependencies like X11 and GL. These will be provided by separate ports
like x11/hs-x11-ghc using the "Cabal"-mechanism (a framework for installing
additional libraries into Haskell environments like GHC and NHC).
Accordingly, the libraries will put their files into a subdirectory of GHC.
List of libraries that have been split off: ALUT GLUT HGL OpenAL OpenGL X11
Also, finally remove dependency on devel/readline: the current readline in
base has all the features we need.
Bump PORTREVISION accordingly.
Tested through Tinderbox runs on lang/ghc and devel/darcs. Please be patient
for the supporting libraries to roll in in the next few days. All screwups
are my fault only and should not be attributed to haskell@.