Extended Cabal configuration to allow builds for GHC < 7.4

curry-frontend.cabal

@@ -32,6 +32,8 @@ Executable cymake
   Main-is:        cymake.hs
   Build-Depends: base == 4.*, curry-base == 0.3.10
     , containers, directory, either, mtl, process, transformers, syb
+  if impl(ghc < 7.4)
+    Build-Depends: either < 4, contravariant < 0.5, semigroupoids < 3.0.3
   ghc-options: -Wall
   Other-Modules:
       Base.CurryTypes