omg, it compiles.

* I'm surprised there are no link errors tho.
* added libyaml submodule
* modified makefile for emscripten build
* #ifdefed out SDL_GetKeyState(), because it's not available for some reason.
emscripten build now embeds pcx files and other data.
removed -O3 flag from emscripten build
noanims in emscripten
squelched some warnings