Added test to verify connection leakages
Merge remote-tracking branch 'upstream/master' into closing_connections
Merge pull request #141 from relops/closing_connections

Transplant test to demonstrate leaking connections
Fix data race when reading conn.isClosed
Only reconnect a host once, defensive locking around close.

Prevent some wait conditions and fail fast when a connection is closed.
Only report to the cluster once that the connection is closed.
Always set read deadline when reading
If the session is closed dont attempt queries
Try all connections from the current position until one is available
Use better error messages when a cluster is unavailable
Fix comments
Index out of bounds
Add a test to check reopening connections after an error
Wait for connections to at least run