[ydl-gen] Correction to Audio over remote X11

[Jim Hart]

I originally said that only Thunderbird audio was audible on the local 
machine. It actually appears to be any program that causes the default 
"boop" sound. vi, for example, if I try to do something it can't handle, 
creates the same audible "boop".

I've gone into the Control Center>Sound & Multimedia>Sound System. In 
the aRTs tab, all the options are checked, including "Enable network 
transparency" and "Exchange security and reference info over the X11 
server", but clicking the "Test Sound" button results in only silence.

The "Sound I/O" tab is set to "Autodetect", and that's the only option.