v0.9.0

Major:

• Rewrites CRuntime.load and all CRDTs' load functions to allow loading at any time. If there is already a non-trivial state, the loaded state is merged with that one, in the style of state-based CRDTs.
• load functions now emit events describing their changes (including incremental changes during merging). This eliminates the need for special cases to refresh the display after loading.

Minor API changes:

• Add Position type (alias for string) to IList.
• Remove info in CRuntime.transact. Instead, apps should use their own CMessenger.
• CRuntime events: remove Load, instead emitting Transaction. Also remove isLoaded.
• CRDT meta: replace vectorClockGet with vectorClock interface; in Collab.load, use type CRDTSavedStateMeta instead of CRDTMessageMeta.
• Remove option to return null from Collab.save. Also, add option to pass null to Collab.load, but with a different meaning from before (tied to Collab.canGC).

Minor behavior changes:

• CSet.add is now a pure CRDT operation, hence can be used with RunLocallyLayer.
• CSet.fromID will remember deleted values (hence return non-undefined) until the end of the current Transaction. This avoids surprises where you try to reference a just-deleted value in an event handler (e.g., see the comments in CMap's internal event handlers).
• Deduplicate messages in CausalMessageBuffer.

Other:

• Collab tests for most concurrent ops, merging, and events.
• Add Istanbul code coverage checker to the crdts package. Run with npm run coverage.

Alpha software - API subject to change.