Merge remote-tracking branch 'remotes/amit-migration/tags/for-2.3-2' into staging

Migration pull for 2.3.  Mostly moving the code to the migration/
directory, and updating MAINTAINERS.

I've also folded my other MAINTAINERS update patches into this, as
they're small by themselves.

# gpg: Signature made Tue 16 Dec 2014 12:21:24 GMT using RSA key ID 854083B6
# gpg: Good signature from "Amit Shah <amit@amitshah.net>"
# gpg:                 aka "Amit Shah <amit@kernel.org>"
# gpg:                 aka "Amit Shah <amitshah@gmx.net>"

* remotes/amit-migration/tags/for-2.3-2:
  MAINTAINERS: Update for migrated migration code
  Split the QEMU buffered file code out
  Split struct QEMUFile out
  Remove migration- pre/post fixes off files in migration/ dir
  Start migrating migration code into a migration directory
  qmp-command.hx: add missing docs for migration capabilites
  cpu: verify that block->host is set
  cpu: assert host pointer offset within block
  exec: add wrapper for host pointer access
  MAINTAINERS: add include files to virtio-serial entry
  MAINTAINERS: add entry for virtio-rng
  MAINTAINERS: migration: add vmstate static checker files
  MAINTAINERS: Add myself to migration maintainers

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