patch applied (cabal): Improve hangling of the title and prolog for haddock docs

[Duncan Coutts]

Fri Aug  3 19:15:38 PDT 2007  Duncan Coutts <duncan at haskell.org>
  * Improve hangling of the title and prolog for haddock docs
  Only include ": " in the title if it has a synopsis to use as subtitle
  Use the description as the prolog, or if that's empty we use the synopsis.
  Do the same for executables, fixing bug #142.

    M ./Distribution/Simple/Haddock.hs -4 +14