patch applied (cabal): Use pkg-config to check for the packages specified in "pkgconfig-depends:"

[Duncan Coutts]

Fri Aug 31 10:10:14 PDT 2007  Duncan Coutts <duncan at haskell.org>
  * Use pkg-config to check for the packages specified in "pkgconfig-depends:"
  And fill out the includeDirs, extraLibs, extraLibDirs, ccOptions and ldOptions
  with the results from pkg-config --cflags --libs

    M ./Distribution/Simple/Configure.hs -10 +87
    M ./Distribution/Simple/Program.hs +8