patch applied (cabal): Rename interfacedir to haddockdir

[Duncan Coutts]

Fri Dec  7 06:28:24 PST 2007  Duncan Coutts <duncan at haskell.org>
  * Rename interfacedir to haddockdir
  Since it really only refers to haddock interfaces, so interface is too
  general a term. Cannot push to 1.2 branch as it changes the api.

    M ./Distribution/Simple/Configure.hs -1 +1
    M ./Distribution/Simple/Install.hs -1 +1
    M ./Distribution/Simple/InstallDirs.hs -17 +14
    M ./Distribution/Simple/Register.hs -8 +7
    M ./Distribution/Simple/Setup.hs -4 +4