SV8 StreamHeader documentation: number of channels

[getID3]

Now that SV8 is finally "final", I've extended getID3() to support it. A few hours coding later it all seems to be working OK, except for the "channel count" value in the Stream Header Packet. The documentation seems slightly off here -- it shows a value range of 1..16, but fails to clarify that the stored value is 0..15 and the actual number of channels is this +1 (so mono audio is stored as "0", stereo is stored as "1", etc).