Volume Control

MusicCat should control Winamp's volume
Have a base volume level (0-255 as winamp's native setting values)
Then an adjusting volume multiplier (generally 0.0 to 2.0), to multiply the base. 2 to 3 digits of precision is expectable.
Volume of course is capped at 255.
Optional song type argument to check the currently-playing song is of the right type as the !volume command wants
