Add connection scheduler

[mycognosist]

Here's my first-pass at a very basic connection scheduler:

There are two connection queues: eager and lazy (think of better names). All peers-to-be-dialed start in the eager queue and one peer is dialed every n seconds. If a connection attempt fails, the peer is moved to the lazy queue. One peer from the lazy queue is dialed every n x 10 seconds (or similar). If a connection attempt succeeds, the peer is moved back to the eager queue.

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• Combine (address, public_key) data from replication.toml with connection data passed via --connect CLI option
  • This will probably require a small refactor...