BUG: compression: disable auto-close and enable MSG_MORE during transfer

BUG: compression: disable auto-close and enable MSG_MORE during transfer

We don't want the lower layer to forward a close while we're compressing,
and we want the system to fuse outgoing TCP segments using MSG_MORE as
much as possible to save round trips that can emerge from sending short
packets with a PUSH flag.

A test on a remote busy DSL line consisting in compressing a 100MB file
on the fly full of zeroes only showed a transfer rate of a few kB/s due
to these round trips.