ogg123: input buffer drains not handled

The following bug was copied from Debian BTS bug #198765:

ogg123 don't handle input buffer drains. There should be an option to
make ogg123 prebuffer input 'til -p when the input buffer is drained (or
goes below a certain level).

This is needed when, for certain reasons, the input buffer reaches 0
(VBR files over network) and the output buffer becomes empty (audio
starts dropping for an undefinitely amount of time).

I actually overcome to this by scroll-locking the terminal for a certain
amount of seconds, and then unlock. This way the output buffer stops,
while the input buffer gets filled thanks to the TCP-stack queue.