Merge remote-tracking branch 'remotes/kevin/tags/for-upstream' into staging

Block layer patches:

- block: Remove bdrv_read() and bdrv_write()
- qemu-img: Allow rebase with no input base
- blockjob: Fix coroutine thread after AioContext change
- MAINTAINERS updates for pflash, curl and gluster

# gpg: Signature made Fri 10 May 2019 16:39:54 BST
# gpg:                using RSA key 7F09B272C88F2FD6
# gpg: Good signature from "Kevin Wolf <kwolf@redhat.com>" [full]
# Primary key fingerprint: DC3D EB15 9A9A F95D 3D74  56FE 7F09 B272 C88F 2FD6

* remotes/kevin/tags/for-upstream:
  iotests: Add test for rebase without input base
  qemu-img: Use zero writes after source backing EOF
  qemu-img: Allow rebase with no input base
  qcow2: Remove BDRVQcow2State.cluster_sectors
  block: Remove bdrv_read() and bdrv_write()
  vvfat: Replace bdrv_{read,write}() with bdrv_{pread,pwrite}()
  vdi: Replace bdrv_{read,write}() with bdrv_{pread,pwrite}()
  qcow2: Replace bdrv_write() with bdrv_pwrite()
  qemu-img: Use IEC binary prefixes for size constants
  test-block-iothread: Job coroutine thread after AioContext switch
  blockjob: Fix coroutine thread after AioContext change
  qemu-iotests: Fix cleanup for 192
  MAINTAINERS: Add an entry for the Parallel NOR Flash devices
  MAINTAINERS: Downgrade status of block sections without "M:" to "Odd Fixes"
  block: remove bs from lists before closing

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