Merge remote-tracking branch 'remotes/stefanha/tags/net-pull-request' into staging

# gpg: Signature made Thu Mar 12 20:06:50 2015 GMT using RSA key ID 81AB73C8
# gpg: Good signature from "Stefan Hajnoczi <[email protected]>"
# gpg:                 aka "Stefan Hajnoczi <[email protected]>"

* remotes/stefanha/tags/net-pull-request:
  tests: rtl8139: test timers and interrupt
  net: synchronize net_host_device_remove with host_net_remove_completion

Signed-off-by: Peter Maydell <[email protected]>