Redesign all the things

[PsychoLlama]

I've been working on this for quite a while, but it's all been in the dark, hidden by cover of shadow. Hopefully the issue helps raise visibility for anyone who's curious.

I'm tracking progress in the wiki.

Redesign Goals

• Add support for more than one type of CRDT in the graph (e.g. text documents).
• Require databases to define a schema.
• Replace read & write APIs with bulk-only implementations.
• Add support for ordered lists of unbounded size (CouchDB-style views).
• Distinguish reads from subscriptions so memory doesn't grow unbounded.