[Libguestfs] [PATCH libnbd v2 0/6] Test connection states.

[Richard W.M. Jones]

Patch 1/6 was posted before and I didn't change it:

  https://www.redhat.com/archives/libguestfs/2019-May/thread.html#00134

That doesn't necessarily mean I shouldn't change it, I'm posting
it again because the other patches depend on it.

The main change in this series is we add three new API functions:

nbd_aio_is_created    - connection has just been created
nbd_aio_is_connecting - is connecting or handshaking / option negotiation
nbd_aio_is_processing - is issuing or receiving a reply

Also in this change I used nbd_aio_is_connecting to simplify the
handling of synchronous connects.

Rich.