Merge remote-tracking branch 'remotes/maxreitz/tags/pull-block-2020-03-11' into staging

Merge remote-tracking branch 'remotes/maxreitz/tags/pull-block-2020-03-11' into staging

Block patches for the 5.0 softfreeze:
- qemu-img measure for LUKS
- Improve block-copy's performance by reducing inter-request
  dependencies
- Make curl's detection of accept-ranges more robust
- Memleak fixes
- iotest fix

# gpg: Signature made Wed 11 Mar 2020 13:19:01 GMT
# gpg:                using RSA key 91BEB60A30DB3E8857D11829F407DB0061D5CF40
# gpg:                issuer "mreitz@redhat.com"
# gpg: Good signature from "Max Reitz <mreitz@redhat.com>" [full]
# Primary key fingerprint: 91BE B60A 30DB 3E88 57D1  1829 F407 DB00 61D5 CF40

* remotes/maxreitz/tags/pull-block-2020-03-11:
  block/block-copy: hide structure definitions
  block/block-copy: reduce intersecting request lock
  block/block-copy: rename start to offset in interfaces
  block/block-copy: refactor interfaces to use bytes instead of end
  block/block-copy: factor out find_conflicting_inflight_req
  block/block-copy: use block_status
  block/block-copy: specialcase first copy_range request
  block/block-copy: fix progress calculation
  job: refactor progress to separate object
  block/qcow2-threads: fix qcow2_decompress
  qemu-img: free memory before re-assign
  block/qcow2: do free crypto_opts in qcow2_close()
  iotests: Fix nonportable use of od --endian
  block/curl: HTTP header field names are case insensitive
  block/curl: HTTP header fields allow whitespace around values
  iotests: add 288 luks qemu-img measure test
  qemu-img: allow qemu-img measure --object without a filename
  luks: implement .bdrv_measure()
  luks: extract qcrypto_block_calculate_payload_offset()

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