ENG-5355: Make sure that responses for requeued snapshots get back to
the original requester.
tnxid2: when time's up, terminate, don't try to shutdown threads as cluster may be in a state of disrepair
voltkvqa: jstack all threads on no progress exit
jenkins tools: vary slaves: change host volt12c to RH5
Merge pull request #1102 from VoltDB/eng5355

ENG-5355, r=jhugg
Merge branch 'master' of github.com:VoltDB/voltdb into ENG-5730-EE-cleanup
clean up search key member variables also