* provide a skeleton hint protocol for rpc apis
* more
* more self.custom_get_connections = None
* fix RpcApiProtocol.service hinting
* catch up with RpcApiProtocol._state_changed()
* FullNode.server is now non-optional. 'ish
* drop another todo
* custom_get_connections -> get_connections
* just make get_connections() a mandatory method with a helper provided
* lots
* try again
* ._start_with_fingerprint()
* fill out the Service generic parameter in start scripts
* ... instead of pass
* add docstrings to the protocols
* remove no longer needed hasattr/not None checks
* remove outdated comment
* refactor Harvester._is_shutdown to ._shut_down
* attempt to save time hashing PeerInfo objects in introducer, by moving attributes from hash tables into the peer object itself, where it belongs
* only remove peers after a few failures in a row, not immediately. Ensure we don't check peers too frequently.
