Add os-is-bootstrap-host element and script

As a very temporary master election we are predetermining a host to be
used as the 'bootstrap host'. Also changing mysql, rabbitmq, and
reset-db to use this script.

This requires Change-Id: I85399019c5fc448e98362ef832988abc8d9d459d

Change-Id: I1369926eb428ee1e3e4af861dc76ffe82a07f629
Merge "Add os-is-bootstrap-host element and script"