Merge branch 'staging'

http://hydra.nixos.org/eval/1234895
The mass errors on Hydra seem transient; I verified ghc on i686-linux.
Only darwin jobs are queued ATM. There's a libpng security update
included in this merge, so I don't want to wait too long.

pkgs/development/libraries/mesa/default.nix

@@ -22,7 +22,7 @@ else
 */
 
 let
-  version = "11.0.5";
+  version = "11.0.8";
   # this is the default search path for DRI drivers
   driverLink = "/run/opengl-driver" + stdenv.lib.optionalString stdenv.isi686 "-32";
 in
@@ -38,7 +38,7 @@ stdenv.mkDerivation {
         + head (splitString "." version) + ''.x/${version}/mesa-${version}.tar.xz'')
       "https://launchpad.net/mesa/trunk/${version}/+download/mesa-${version}.tar.xz"
     ];
-    sha256 = "9c255a2a6695fcc6ef4a279e1df0aeaf417dc142f39ee59dfb533d80494bb67a";
+    sha256 = "5696e4730518b6805d2ed5def393c4293f425a2c2c01bd5ed4bdd7ad62f7ad75";
   };
 
   prePatch = "patchShebangs .";