Make volume tooltip & default/step use same range

[j_hallgren]

This started as thread viewtopic.php?t=33412:
Given that volume tooltip shows values of 0-97, (presuming a 0-100 range?) when adjusted by mouse, the default and steps should use a matching value scheme, and not a 0-1024 scale, which makes NO sense...either that...or tooltip should also thus show 0-1024!

And when adjusting by keyboard, one can set volume to a maximum higher than 100%, all the way up to 400%, which is just plain wrong!