Merge remote-tracking branch 'mreitz/tags/pull-block-2016-10-07' into queue-block

Merge remote-tracking branch 'mreitz/tags/pull-block-2016-10-07' into queue-block

Block patches for the block queue.

# gpg: Signature made Fri Oct  7 14:14:45 2016 CEST
# gpg:                using RSA key 0xF407DB0061D5CF40
# 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-2016-10-07:
  dmg: Move libbz2 code to dmg-bz2.so
  module: Don't load the same module if requested multiple times
  scripts: Allow block module to not define BlockDriver

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