chat-cli: Make more fully-featured
chat-cli: Make more fully-featured

Brings it largely up to parity with Talk, save for features relating to:
- presence & nicknames
- circle management (permissions, sources)
- deprecated message types

In addition to implementing remaining functionality for basic usage
patterns, makes the following changes:
- glyphs per target, not multiple targets
- assume /~ship/path paths are created/used by the chat-hook

Code cleanup pending.

ngzax/urbit,jfranklin9000/urbit,ngzax/urbit,ngzax/urbit,ngzax/urbit,jfranklin9000/urbit,urbit/urbit,ngzax/urbit,ngzax/urbit,jfranklin9000/urbit,jfranklin9000/urbit,urbit/urbit,ngzax/urbit,jfranklin9000/urbit,urbit/urbit,urbit/urbit,jfranklin9000/urbit,urbit/urbit,urbit/urbit,jfranklin9000/urbit,urbit/urbit