Two improvements in the pgf-shell example

1. Like pgf-translate, it now shows one result at a time, press Enter to get
   more results.
2. You can load a new grammar with the command 'i <path-to-pgf>'

src/runtime/haskell-bind/pgf2-bind.cabal

@@ -22,7 +22,9 @@ library
   build-depends:       base >=4.3, bytestring >=0.9,
                        containers
   -- hs-source-dirs:      
+  default-language:    Haskell2010
   build-tools:         hsc2hs
+
   extra-libraries:     gu pgf
   cc-options:          -std=c99
   default-language:    Haskell2010
@@ -30,7 +32,7 @@ library
 executable pgf-shell
   main-is:             pgf-shell.hs
   hs-source-dirs:      examples
-  build-depends:       base, pgf2-bind, containers
+  build-depends:       base, pgf2-bind, containers, mtl, lifted-base
   default-language:    Haskell2010
   if impl(ghc>=7.0)
     ghc-options: -rtsopts