SSB-RPC

The remote procedure calls used by ssb.

Scuttlebutt has a plugin system that allows adding support for more rpcs. This module uses features to control which rpcs are exposed. By default, this includes the rpcs of the core scuttlebot module, and the rpcs of the plugins which are bundled with scuttlebot.

The rpcs for other plugins will be implemented in different crates, but can be exposed (behind a non-default feature flag) in this crate as well.