patch applied (cabal): separate build and output directory for Hugs build

[Ross Paterson]

Sat May 12 17:15:02 PDT 2007  Ross Paterson <ross at soi.city.ac.uk>
  * separate build and output directory for Hugs build
  
  Hugs requires a separate directory for the output files from the directory
  containing the preprocessed files.  The --scratchdir option now sets the
  former (and thus has an effect only for Hugs).
  
  This repairs the Hugs build.

    M ./Distribution/Simple.hs -5 +5
    M ./Distribution/Simple/Configure.hs +1
    M ./Distribution/Simple/Hugs.hs -5 +8
    M ./Distribution/Simple/Install.hs -1 +2
    M ./Distribution/Simple/LocalBuildInfo.hs -1 +3
    M ./doc/Cabal.xml -4 +3