Tween.js

-Adding a tweenjs lib.
-Added a update function on the game that ticks and updates the
tweening.
Scrolling Combat text!

-rendering is now done every tick via requestAnimationFrame.  This is
so we get smooth rendering with tweened combat text.
-modified rot.js to allow for drawing colored text (doesn't work yet).
-floor tiles are just blank text.  it was too cluttered.