Switch some infra jobs to use bare precise nodes

Rename the jjb file to be less anachronistic.

Make these jobs mark their nodes as single-use.

Make sure there are at least enough nodes ready to fully test
one change.

Change-Id: I9bbb7cebf8f3a7b9e69d77f691505efd88972dc5
Merge "Switch some infra jobs to use bare precise nodes"