SDL: cleanup and add patch to discover extensions

pkgs/development/libraries/SDL_net/default.nix

@@ -11,21 +11,12 @@ stdenv.mkDerivation rec {
     sha256 = "1d5c9xqlf4s1c01gzv6cxmg0r621pq9kfgxcg3197xw4p25pljjz";
   };
 
-  propagatedBuildInputs = [SDL];
+  propagatedBuildInputs = [ SDL ];
 
-  postInstall = ''
-    sed -i -e 's,"SDL.h",<SDL/SDL.h>,' \
-    -e 's,"SDL_endian.h",<SDL/SDL_endian.h>,' \
-    -e 's,"SDL_version.h",<SDL/SDL_version.h>,' \
-    -e 's,"begin_code.h",<SDL/begin_code.h>,' \
-    -e 's,"close_code.h",<SDL/close_code.h>,' \
-      $out/include/SDL/SDL_net.h
-
-    ln -sv $out/include/SDL/SDL_net.h $out/include/
-  '';
-
-  meta = {
+  meta = with stdenv.lib; {
     description = "SDL networking library";
-    platforms = stdenv.lib.platforms.unix;
+    platforms = platforms.unix;
+    license = licenses.zlib;
+    homepage = "https://www.libsdl.org/projects/SDL_net/release-1.2.html";
   };
 }