Merge remote-tracking branch 'remotes/armbru/tags/pull-ivshmem-2015-11-25' into staging

ivshmem patches for 2.5

# gpg: Signature made Wed 25 Nov 2015 09:25:38 GMT using RSA key ID EB918653
# gpg: Good signature from "Markus Armbruster <armbru@redhat.com>"
# gpg:                 aka "Markus Armbruster <armbru@pond.sub.org>"

* remotes/armbru/tags/pull-ivshmem-2015-11-25:
  ivshmem: Rename property memdev to x-memdev for 2.5
  ivshmem: Mark questionable socket type test FIXME
  tests/ivshmem-test: Supply missing initializer in get_device()
  qemu-doc: Fix ivshmem usage example with shm=...
  qemu-doc: Fix ivshmem example markup

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