NCBC-396: Log the creation of client instances

Serializes the client configuration and writes it to the log appender when
log level is set to Info.

Change-Id: I522f0330182d8f93b7bf04af3084079ab631ce6f
Reviewed-on: http://review.couchbase.org/33693
Reviewed-by: Jeffry Morris <jeffrymorris@gmail.com>
Tested-by: Jeffry Morris <jeffrymorris@gmail.com>