[jhc] transformers package on JHC

[Henning Thielemann]

For those people who want to use the 'transformers' package on JHC I have 
made a patch:
   http://code.haskell.org/~thielema/transformers-jhc.patch

I hesitate to push this to the 'transformers' main branch, since it 
contains only several syntactic replacements like:

  do ~(a,b) <- act

replaced by

  do ab <- act
     let (a,b) = ab


How about replacing 'mtl' dependency by 'transformers' in JHC's code? This 
would free us from some functional dependencies and might bring us closer 
to a JHC compiled JHC.