Merge remote-tracking branch 'remotes/juanquintela/tags/migration/20180115' into staging

migration/next for 20180115

# gpg: Signature made Mon 15 Jan 2018 11:51:00 GMT
# 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/20180115: (27 commits)
  migration: remove notify in fd_error
  migration: remove some block_cleanup_parameters()
  migration: put the finish part into a new function
  migration: major cleanup for migrate iterations
  migration: cleanup stats update into function
  migration: use switch at the end of migration
  migration: introduce migrate_calculate_complete
  migration: introduce downtime_start
  migration: move vm_old_running into global state
  migration: split use of MigrationState.total_time
  migration: remove "enable_colo" var
  migration: qemu_savevm_state_cleanup() in cleanup
  migration: assert colo instead of check
  migration: finalize current_migration object
  migration: Guard ram_bytes_remaining against early call
  migration: add postcopy total blocktime into query-migrate
  migration: add blocktime calculation into migration-test
  migration: postcopy_blocktime documentation
  migration: calculate vCPU blocktime on dst side
  migration: add postcopy blocktime ctx into MigrationIncomingState
  ...

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