* Color can now accept keyword args with colors eg `Color('red', alpha=180)`
* Default use of Color(int) is rgb. Eg. `Color(0xFF0000, 0.5)` is half opaque red.
* Keyword args for Color accepts argb and rgba. Eg. `Color(argb=0xFF00FF)`
* Keyword args added for `hue`, `saturation`, `lightness` and `alpha`.
* Color has `.argb`, `.rgb` and `.rgba` properties. These can be set: `color.argb = 0xFF0000FF`
* `Color.hsl_to_int` does not require creating a Color object. hsl init, calls the function.
* `.hue` had a bug which gave the hue in turns. It should have given hue in degrees.