Merge remote-tracking branch 'remotes/juanquintela/tags/migration/20151125' into...

migration/next for 20151125

# gpg: Signature made Wed 25 Nov 2015 14:28:47 GMT using RSA key ID 5872D723
# gpg: Good signature from "Juan Quintela <quintela@redhat.com>"
# gpg:                 aka "Juan Quintela <quintela@trasno.org>"

* remotes/juanquintela/tags/migration/20151125:
  block-migration: limit the memory usage
  Assume madvise for (no)hugepage works

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