This fixes some issues with the client announcing itself in the bridge swarm, particularly in the pinging of injectors, which may eventually leave the client out of the swarm and thus unreachable to others, especially after being running for an extended period. Enhancements: - Ignore DHT martians in the `bt-bep5` utility. As a result, its output and that of `ping-swarm` are less cluttered and more useful. Bugfixes: - Fix the computation of pauses between pinging injectors at the client, so that pings are not too far apart, which may cause the client's entry in the bridge swarm to become questionable. - Fix the selection of injectors to be pinged in each round, avoiding never actually pinging interesting injectors if they are located after a certain point in the internal list of nodes seen in the injector swarm.