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

# gpg: Signature made Tue 22 Dec 2015 08:52:55 GMT using RSA key ID 81AB73C8
# gpg: Good signature from "Stefan Hajnoczi <stefanha@redhat.com>"
# gpg:                 aka "Stefan Hajnoczi <stefanha@gmail.com>"

* remotes/stefanha/tags/block-pull-request:
  sdhci: add optional quirk property to disable card insertion/removal interrupts
  sdhci: don't raise a command index error for an unexpected response
  sd: sdhci: Delete over-zealous power check
  scripts/gdb: Fix a python exception in mtree.py
  parallels: add format spec
  block/mirror: replace IOV_MAX with blk_get_max_iov()
  block: replace IOV_MAX with BlockLimits.max_iov
  block-backend: add blk_get_max_iov()
  block: add BlockLimits.max_iov field
  virtio-blk: trivial code optimization

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