patch applied (cabal): Fix hscolour code so it only outputs the css once per-lib or exe

[Duncan Coutts]

Fri Dec  7 05:03:09 PST 2007  Duncan Coutts <duncan at haskell.org>
  * Fix hscolour code so it only outputs the css once per-lib or exe
  Rather than for every module in the lib. Tidy the code up a little too.

    M ./Distribution/Simple/Haddock.hs -10 +11