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

Block patches for 2.0.0

# gpg: Signature made Fri 04 Apr 2014 20:25:08 BST using RSA key ID C88F2FD6
# gpg: Good signature from "Kevin Wolf <kwolf@redhat.com>"

* remotes/kevin/tags/for-upstream:
  dataplane: replace iothread object_add() with embedded instance
  iothread: make IOThread struct definition public
  dma-helpers: Initialize DMAAIOCB in_cancel flag
  block: Check bdrv_getlength() return value in bdrv_append_temp_snapshot()
  block: Fix snapshot=on for protocol parsed from filename
  qemu-iotests: Remove CR line endings in reference output
  block: Don't parse 'filename' option
  qcow2: Put cache reference in error case
  qcow2: Flush metadata during read-only reopen
  iscsi: Don't set error if already set in iscsi_do_inquiry

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