[MAJOR - UNFUNCTIONAL / change-fix-feature]

migrated (mostly) from C to C++, moved *.c to *.cpp and *.h to *.hpp

engine.hpp, engine.cpp:
        made a GameEngine class for all things engine-related
        changed returns, arguments, function headers, printf to std::cout, etc.
        more variables, struct that holds only {x, y} or {w, h} instead of using SDL_Rect

engine.cpp:
        that commented free-ing code would screw up when SDL_GetVideoModes returned -1, fixed
        handler for movement and updates crosshair position only (there isn't even a crosshair now)
	added render() function, it renders the world and stuff, only material rendering so far