Merge remote-tracking branch 'mreitz/tags/pull-block-2017-11-17' into queue-block

Block patches for 2.11.0-rc2

# gpg: Signature made Fri Nov 17 18:22:07 2017 CET
# gpg:                using RSA key F407DB0061D5CF40
# gpg: Good signature from "Max Reitz <mreitz@redhat.com>"
# Primary key fingerprint: 91BE B60A 30DB 3E88 57D1  1829 F407 DB00 61D5 CF40

* mreitz/tags/pull-block-2017-11-17:
  iotests: Make 087 pass without AIO enabled
  block: Make bdrv_next() keep strong references
  qcow2: Fix overly broad madvise()
  qcow2: Refuse to get unaligned offsets from cache
  qcow2: Add bounds check to get_refblock_offset()
  block: Guard against NULL bs->drv
  qcow2: Unaligned zero cluster in handle_alloc()
  qcow2: check_errors are fatal
  qcow2: reject unaligned offsets in write compressed
  iotests: Add test for failing qemu-img commit
  tests: Add check-qobject for equality tests
  iotests: Add test for non-string option reopening
  block: qobject_is_equal() in bdrv_reopen_prepare()
  qapi: Add qobject_is_equal()
  qapi/qlist: Add qlist_append_null() macro
  qapi/qnull: Add own header

Signed-off-by: Kevin Wolf <kwolf@redhat.com>