New logic handling re-delivery of packets

Previously, Tigase would retry deliverying command packets that failed to send after a brief delay of 60 seconds. This new method can provide relief in sutations where command packet queues can get full. The new logic works like this: The delay for retries, after the first delay of 60 seconds will increase by a factor of 1.5, so the 2nd retry will then be 90 seconds, and then 135 and so on, until the retry limit has been reached (default is 15). Included in this is a new setting for setting the retry count, available here.