Some databases (e.g. Oracle) can conceal multiple server nodes behind a single connection URL. So if we timeout while trying to connect to one node, we can still hope to connect to one of the other nodes. However, this assumes that the connection timeout is smaller than BTM's connection acquisition timeout.

Allow the connection test's timeout to be configured independently.
Merge pull request #36 from rankinc/connection-test-timeout-2

Add a new configuration option for connection test timeout.