Merge commit '3e39789b64b01444b6377a043894e6b9a3ba6cbb' into upstream-merge

Merge commit '3e39789b64b01444b6377a043894e6b9a3ba6cbb' into upstream-merge

* commit '3e39789b64b01444b6377a043894e6b9a3ba6cbb':
  Revert "block: prevent multiwrite_merge from creating too large iovecs"
  make: qemu-img depends on config-host.h
  reduce number of reinjects on ACK
  block: prevent multiwrite_merge from creating too large iovecs
  block: fix cache flushing in bdrv_commit
  QMP: Fix asynchronous events delivery
  vnc: Use inet_strfamily()
  net: inet_strfamily(): Better unknown family report
  net: Make inet_strfamily() public
  virtio-serial: Use MSI vectors for port virtqueues
  Move virtio-serial to Makefile.objs
  virtio-serial: Add a 'virtserialport' device for generic serial port support
  virtio-serial-bus: Add ability to hot-unplug ports
  virtio-serial-bus: Add a port 'name' property for port discovery in guests
  virtio-serial-bus: Maintain guest and host port open/close state

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>