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

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

Block pull request

# gpg: Signature made Fri 14 Feb 2014 17:26:30 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:
  block: Open by reference will try device then node_name.
  block: Relax bdrv_lookup_bs constraints.
  blockdev: Fix wrong usage of QDECREF causing snapshoted quorum to crash on close.
  block: mirror - use local_err to avoid NULL errp
  qemu-iotests: Don't run 005 on vmdk split formats
  block: qemu-iotests - add vhdx log replay tests for qemu-img
  block: qemu-iotests - fix test 070 (vhdx)
  block: Don't throw away errno via error_setg
  block: Add notes to iSCSI's .bdrv_open and .bdrv_reopen_prepare
  blockdev: Remove 'type' parameter from blockdev_init()
  sdhci: Drop unnecessary #include

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