Light Client Daemon

[ebuchman]

Now that the library logic and bisection are nearing completion in #96 and the relevant follow up issues (#110, #111), we should implement the daemon that puts it all together.

This requires:

• initial config with subjective initialization and list of peers
• simple address book to track peers and manage primary/backups
• detection module to make requests from backup peers, search for conflicts, and publish any verified ones
• concrete implementation of the store
• command line tool

To start, let's get a simple command line tool that works in the single peer case with a simple store, and then work on the detection module for detecting conflicts from backup peers.

[ebuchman]

The core of this in the form of the "syncing" loop is working in a basic form in #116

[ebuchman]

Closing for specific issues:

• initial config with subjective initialization and list of peers - Light Node Initialization #293
• simple address book to track peers and manage primary/backups - Light Node Initialization #293 and Light Client Fork Detection #218
• detection module to make requests from backup peers, search for conflicts, and publish any verified ones - Light Client Fork Detection #218 and [light-client] Evidence Reporting #217
• concrete implementation of the store - exists now since the refactor, but ensure it works with the tool re Light Node Initialization #293
• command line tool - basics exist in light-node but needs eg Light Node Initialization #293