patch applied (packages/directory): Add makeRelativeToCurrentDirectory

[Ian Lynagh]

Sat Jun 30 03:58:34 PDT 2007  Ian Lynagh <igloo at earth.li>
  * Add makeRelativeToCurrentDirectory
  Moved from the filepath package, which we now depend on.

    M ./System/Directory.hs +8
    M ./directory.cabal -1 +1