Updating meshlab.

Their build system has changed, and the source tree they distribute too, so the
dependencies changed a bit.
To get meshlab working, I update lib3ds and add levmar.

svn path=/nixpkgs/trunk/; revision=19595

pkgs/development/libraries/lib3ds/default.nix

@@ -4,7 +4,7 @@ stdenv.mkDerivation rec {
   name = "lib3ds-1.3.0";
 
   src = fetchurl {
-    url = "mirror://sourceforge/lib3ds/${name}.zip";
+    url = "http://lib3ds.googlecode.com/files/${name}.zip";
     sha256 = "1qr9arfdkjf7q11xhvxwzmhxqz3nhcjkyb8zzfjpz9jm54q0rc7m";
   };