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

Block pull request

# gpg: Signature made Fri 14 Mar 2014 16:12:14 GMT using RSA key ID 81AB73C8
# gpg: Good signature from "Stefan Hajnoczi <stefanha@redhat.com>"
# gpg:                 aka "Stefan Hajnoczi <stefanha@gmail.com>"
# gpg: WARNING: This key is not certified with a trusted signature!
# gpg:          There is no indication that the signature belongs to the owner.
# Primary key fingerprint: 8695 A8BF D3F9 7CDA AC35  775A 9CA4 ABB3 81AB 73C8

* remotes/stefanha/tags/block-pull-request:
  qemu-iotests: remove 085 and 087 from 'quick' group
  qemu-iotests: add 083 NBD client disconnect tests
  tests: add nbd-fault-injector.py utility
  nbd: close socket if connection breaks
  block: Explicitly specify 'unsigned long long' for VHDX 64-bit constants
  blockdev: Refuse to open encrypted image unless paused

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>