haskell-base64-bytestring: downgraded default version to 0.1.0.3

Michael Snoyman reports that version 0.1.1.0 has serious performance issues:

> import Data.ByteString.Base64
> import Data.ByteString.Char8 (pack)
> import Criterion.Main
>
> main :: IO ()
> main = defaultMain
> [ bench "encode" $ whnf encode $ pack "qwerty"
> ]

On version 0.1.0.3, this takes 229.4312 ns. On 0.1.1.0, it takes 3.556598 ms.
It looks like the problem is coming from the recent addition of URL encoding
(https://github.com/bos/base64-bytestring/commit/f1916d8a86b496cfacd23939b5e3fa10d92abb7b).

svn path=/nixpkgs/trunk/; revision=32632

pkgs/development/libraries/haskell/base64-bytestring/0.1.0.3.nix

···
+{ cabal }:
+
+cabal.mkDerivation (self: {
+  pname = "base64-bytestring";
+  version = "0.1.0.3";
+  sha256 = "0d4j8b1d8z9qr1y446bfkj764xgilk8gw2frj0wn0717y8knvmx3";
+  meta = {
+    homepage = "https://github.com/bos/base64-bytestring";
+    description = "Fast base64 encoding and deconding for ByteStrings";
+    license = self.stdenv.lib.licenses.bsd3;
+    platforms = self.ghc.meta.platforms;
+    maintainers = [
+      self.stdenv.lib.maintainers.andres
+      self.stdenv.lib.maintainers.simons
+    ];
+  };
+})

pkgs/top-level/haskell-packages.nix

···
 
   base64String = callPackage ../development/libraries/haskell/base64-string {};
 
-  base64Bytestring = callPackage ../development/libraries/haskell/base64-bytestring {};
+  base64Bytestring_0_1_0_3 = callPackage ../development/libraries/haskell/base64-bytestring/0.1.0.3.nix {};
+  base64Bytestring_0_1_1_0 = callPackage ../development/libraries/haskell/base64-bytestring/0.1.1.0.nix {};
+  base64Bytestring = self.base64Bytestring_0_1_0_3; # Version 0.1.1.0 has serious performance issues.
 
   baseUnicodeSymbols = callPackage ../development/libraries/haskell/base-unicode-symbols {};