CMake support for mac osx

So I said I was done screwing with libtcod for awhile, but my new laptop thinks otherwise. It is now obligatory to get magecrawl running on it. And so...

This morning I got samples_c to run under Mac OSX. There was a bunch of nonsense with sdl_main and such, but I got it working. Now I need to get the other tools working, clean up the patches, and then create libtcod-net for mac. Then I can get back to magecrawl.