Class ChangesParamsHelper

Set longpoll timeout to MIN_CLIENT_TIMEOUT - 3 second (= 3000 ms). To give the changes request a chance to be answered before the client timeout it is set to 3 seconds less.

Set minimum client timeout to 1 minute (= 60 000 ms). 1 minute is the sort of number that very likely to be used as a client timeout, so it makes sense to set as our minimum client timeout.