Allow building with base-4.7. Patch from Ian Lynagh.

haskeline.cabal

@@ -51,7 +51,7 @@ flag legacy-encoding
 
 Library
     if impl(ghc>=6.11) {
-        Build-depends: base >=4.1 && < 4.7, containers>=0.1 && < 0.6, directory>=1.0 && < 1.3,
+        Build-depends: base >=4.1 && < 4.8, containers>=0.1 && < 0.6, directory>=1.0 && < 1.3,
                        bytestring>=0.9 && < 0.11
     }
     else {