Assigned more time for a slave to become available for pulling updates

Fixed a error in test where update puller pulls update when a slave is not available by making it wait for a while for the slave to become available.
@thobe Thanks a lot! I was wondering how should I throw the exception properly. For the printState method, I really quite like it. A simple "SLAVE" or "TO_SLAVE" helps me a lot to locate the possible error sections in log files quickly. So I assume everyone would also like it too.