Updated me.Font to work with me.Color

Updated me.Font to work with me.Color

only the tween at font_test example acts a bit weird

This is a (possible) solution for https://github.com/melonjs/melonJS/issues/498
We can use the pool to create temporary colors:

```javascript
me.pool.pull("me.Color", 255, 255, 255)
```

Just remember to push the color back into the pool when you're done using it!