SDL now copies Objective-C support files.

Mac OS X projects that use SDL through Objective-C may
require the "SDLmain" support files.

Since these are not strictly header files, they are not
installed into include by default, so we put them in our
libexec folder.

Formula/sdl.rb

@@ -14,7 +14,10 @@ class Sdl <Formula
     system "./configure", "--prefix=#{prefix}", "--disable-debug",
                           "--disable-dependency-tracking",
                           "--disable-video-x11",
-                          "--disable-nasm" # seems essential to build on 10.6
+                          "--disable-nasm"
     system "make install"
+    
+    # Copy source files needed for Ojective-C support.
+    libexec.install Dir["src/main/macosx/*"]
   end
 end