patch applied (cabal-install): Update world file entries ignoring version constraints

[Duncan Coutts]

Sun May  9 20:24:57 PDT 2010  Duncan Coutts <duncan at haskell.org>
  * Update world file entries ignoring version constraints
  Otherwise it is easy to add impossible constraints to the world file.
  cabal install 'foo > 1' && cabal install 'foo < 1'
  Would give us a world file with both constraints.

    M ./Distribution/Client/World.hs -5 +5

View patch online:
http://darcs.haskell.org/cgi-bin/darcsweb.cgi?r=cabal-install;a=darcs_commitdiff;h=20100510032457-adfee-258492837e33f4d279ba1aebbd34ab4f956ea272.gz