Cabal revisions of category-extras-0.51.2

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

 name:                   category-extras category:               Control, Monads, Comonads version:                0.51.2+x-revision: 1 license:                BSD3 cabal-version:          >= 1.2 license-file:           LICENSE         default:        False  library-        build-depends:  mtl >= 1.1+        build-depends:  mtl >= 1.1 && < 2, base < 4.3         extensions:                 CPP,                 EmptyDataDecls,