Updated Annotator to e2188905 (typed-packaging branch)

Followed packaging changes. (New plugins, etc.)
Update Annotator to bd4f41f (typed-packaging branch)

Follow the packaging changes.
Update Annotator to 2000a6570 (typed-packaging branch)
Merge pull request #939 from hypothesis/typed-packaging

Incorporate the latest work done on Annotator's typed-packaging branch.

There are almost no H-related changes here; it's only about Annotator internal changes.
(Packaging and cosmetic fixed, and a few smaller bug fixes.)