/*
 * Set an equalizer band value.
 *
 * Note: legal band indices range from 0 to 9 instead of 1 to 10.
 * 
 * This method raises an Xmms::Error exception if XMMS is not running,
 * or an ArgumentError exception if the band index is out of range.
 *
 * Example:
 *   remote.set_band 2, 0.5
 *
 */
static VALUE xr_eq_set_band(VALUE self, VALUE band, VALUE val) {