Initial pass at adding support for input/graphics support with Rust SDL.
This gets the basic framework in place but there are some bugs lurking ROMs look wrong when rendered.
Add key binding support.
Fix bugs - clearscreen and return were not bumping up the PC, width/height were backwards when drawing.
Fix warnings related to unnecessary parentheses and deprecated methods.
Add a timer to help maintain a consistent framerate.
Merge branch 'master' of https://github.com/pdovy/rustychip8 into sdl-support