Clear the queue when a node is wiped
Also wipe before shutting down

Don't rely on the client to be able to tell the nodes to wipe.
Change the name of shutdown-nodes! to wipe-and-shutdown-nodes!
Merge pull request #76 from eric/clear-queue-with-wipe

Clear the queue when a node is wiped
Update last-leader-msg-time on successful election

If a vnode election is successful, update last-leader-msg-time to the current
time.
Merge pull request #88 from eric/update-last-leader-msg-time-on-master

Update last-leader-msg-time on successful election