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

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

Block patches

# gpg: Signature made Fri 15 Aug 2014 14:07:42 BST using RSA key ID C88F2FD6
# gpg: Good signature from "Kevin Wolf <[email protected]>"

* remotes/kevin/tags/for-upstream: (59 commits)
  block: Catch !bs->drv in bdrv_check()
  iotests: Add test for image header overlap
  qcow2: Catch !*host_offset for data allocation
  qcow2: Return useful error code in refcount_init()
  mirror: Handle failure for potentially large allocations
  vpc: Handle failure for potentially large allocations
  vmdk: Handle failure for potentially large allocations
  vhdx: Handle failure for potentially large allocations
  vdi: Handle failure for potentially large allocations
  rbd: Handle failure for potentially large allocations
  raw-win32: Handle failure for potentially large allocations
  raw-posix: Handle failure for potentially large allocations
  qed: Handle failure for potentially large allocations
  qcow2: Handle failure for potentially large allocations
  qcow1: Handle failure for potentially large allocations
  parallels: Handle failure for potentially large allocations
  nfs: Handle failure for potentially large allocations
  iscsi: Handle failure for potentially large allocations
  dmg: Handle failure for potentially large allocations
  curl: Handle failure for potentially large allocations
  ...

Signed-off-by: Peter Maydell <[email protected]>