Cabal revisions of dependent-sum-0.4

Hackage metadata revisions edit the .cabal file after upload; each diff below is one revision.

 name:                   dependent-sum version:                0.4+x-revision: 1 stability:              provisional  cabal-version:          >= 1.6   if impl(ghc < 7.8)     other-modules:      Data.Dependent.Sum.Typeable   -  build-depends:        base >= 3 && <5+  build-depends:        base >= 3 && <4.17   if impl(ghc >= 7.2)     ghc-options:        -trust base