Run early warning / status check builds under personal account

Current status:
A person can log in to Coin UI with any string. That account is never checked via LDAP. Any scheduled build is connecting to OpenNebula using the default account bld.qt.coin and all VMs are visible as that user running them.

Expected status:
A person's log in to Coin is checked via LDAP that it is actually a real account. That account is then used to connect to OpenNebula, and any VM he or she schedules in Coin is run with that account.

Benefit:
We can clearly get graphics to Grafana pointing out how many percentages of our capacity goes to serving RTA or Gerrit stages or personal early checks or what ever else.