patch applied (cabal): flush stdout before running subprograms

[Ross Paterson]

Fri Jan 25 02:20:53 PST 2008  Ross Paterson <ross at soi.city.ac.uk>
  * flush stdout before running subprograms
  
  This is needed to separate Cabal and subprogram output if stdout is
  buffered (e.g. a file), especially if stdout and stderr are the same.

    M ./Distribution/Simple/Utils.hs +1