Request: Change Volume Values

[dasadavid]

Currently you can change the volume max, min and step - which is great, but I have run into a scenario with my chromecast that I was hoping could be accommodated for with a new set of config entries.

Chromecast volume levels range from 1-20, it would be cool if I could replace the 1-100 on the volume slider with 1-20, and that value gets converted correctly so 20=100% volume. (Currently if I set the max to 20, max volume will only ever be 20%.)