The arguments sink_dont_move and source_dont_move have been added to toggle
module automatic unloading when the sink or source were no longer
available, rather than just moving them to the next available
sink/source (via rescue streams).
Reviewed and tweaked by Colin Guthrie.
All seeks/flushes that depend on the playback buffer read pointer cannot
be accounted for properly in the client since it does not know the
actual read pointer. Due to that the clients do not account for it at
all. We need do the same on the server side. And we did, but a little
bit too extreme. While we properly have not applied the changes to the
"request" counter we still do have to apply it to the "missing" counter.
This patch fixes that.
