Merge remote-tracking branch 'remotes/juanquintela/tags/migration/20170421' into staging

migration/next for 20170421

# gpg: Signature made Fri 21 Apr 2017 11:28:13 BST
# gpg:                using RSA key 0xF487EF185872D723
# gpg: Good signature from "Juan Quintela <quintela@redhat.com>"
# gpg:                 aka "Juan Quintela <quintela@trasno.org>"
# Primary key fingerprint: 1899 FF8E DEBF 58CC EE03  4B82 F487 EF18 5872 D723

* remotes/juanquintela/tags/migration/20170421: (65 commits)
  hmp: info migrate_parameters format tunes
  hmp: info migrate_capability format tunes
  migration: rename max_size to threshold_size
  migration: set current_active_state once
  virtio-rng: stop virtqueue while the CPU is stopped
  migration: don't close a file descriptor while it can be in use
  ram: Remove migration_bitmap_extend()
  migration: Disable hotplug/unplug during migration
  qdev: Move qdev_unplug() to qdev-monitor.c
  qdev: Export qdev_hot_removed
  qdev: qdev_hotplug is really a bool
  migration: Remove MigrationState parameter from migration_is_idle()
  ram: Use RAMBitmap type for coherence
  ram: rename last_ram_offset() last_ram_pages()
  ram: Use ramblock and page offset instead of absolute offset
  ram: Change offset field in PageSearchStatus to page
  ram: Remember last_page instead of last_offset
  ram: Use page number instead of an address for the bitmap operations
  ram: reorganize last_sent_block
  ram: ram_discard_range() don't use the mis parameter
  ...

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