blender: Update to 2.74

pkgs/applications/misc/blender/default.nix

···
 with lib;
 
 stdenv.mkDerivation rec {
-  name = "blender-2.73a";
+  name = "blender-2.74";
 
   src = fetchurl {
     url = "http://download.blender.org/source/${name}.tar.gz";
-    sha256 = "114ipidrja6ryi6wv0w55wmh10ikazy24r8js596g7b9fpkzpymc";
+    sha256 = "178i19pz7jl79b4wn92869j6qymawsa0kaw1dxaprbjnqsvcx8qc";
   };
 
   patches = [ ./sm52.patch ];