* Speed up serialization of hostvars by simply using the internal
dictionary used for cached lookups
* Use blocking gets/puts on queues instead of spin locking
* Merge sequential implicitly created blocks
Also adds play information into the hostvars creation, to assure the
variable manager used there has access to vars and vars_files
Fixes#9501Fixes#8213Fixes#7844
James Cammarata
Toshio Kuratomi