Block layer patches

# gpg: Signature made Fri 23 Sep 2016 12:59:46 BST
# gpg:                using RSA key 0x7F09B272C88F2FD6
# gpg: Good signature from "Kevin Wolf <kwolf@redhat.com>"
# Primary key fingerprint: DC3D EB15 9A9A F95D 3D74  56FE 7F09 B272 C88F 2FD6

* remotes/kevin/tags/for-upstream: (33 commits)
  block: Remove BB interface from blockdev-add/del
  qemu-iotests/141: Avoid blockdev-add with id
  block: Avoid printing NULL string in error messages
  qemu-iotests/139: Avoid blockdev-add with id
  qemu-iotests/124: Avoid blockdev-add with id
  qemu-iotests/118: Avoid blockdev-add with id
  qemu-iotests/117: Avoid blockdev-add with id
  qemu-iotests/087: Avoid blockdev-add with id
  qemu-iotests/081: Avoid blockdev-add with id
  qemu-iotests/071: Avoid blockdev-add with id
  qemu-iotests/067: Avoid blockdev-add with id
  qemu-iotests/041: Avoid blockdev-add with id
  qemu-iotests/118: Test media change with qdev name
  block: Accept device model name for block_set_io_throttle
  block: Accept device model name for blockdev-change-medium
  block: Accept device model name for eject
  block: Accept device model name for x-blockdev-remove-medium
  block: Accept device model name for x-blockdev-insert-medium
  block: Accept device model name for blockdev-open/close-tray
  qdev-monitor: Add blk_by_qdev_id()
  ...

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