Switch back to using transaction id in export metadata column because it is necessary for truncation on snapshot restore
ENG-4136: Initialize the command log for rejoin before configuring the
IV2 initiators.  This avoids a race where the IV2 initiator config could
cause messages to arrive and get discarded because the command log
doesn't have a configured file writer.

r=rbetts
Factor out common IV2 initiator code from the rejoin and non-rejoin
paths.

r=rbetts
Merge pull request #319 from VoltDB/ENG-4141

Switch back to using transaction id in export metadata column because it...
Add names to txnid-selfcheck2 threads.
Also fake a jstack on error-induced-exit.
ENG-4173: Update favicons!
Merge branch 'master' into ENG-4068
ENG-4068 implemented 'skinny' version of export on server tests