Support the W3 Web Annotation standard (W3C Recommendation)

[timmhayes]

On 2/23/2017, the W3 published three recommendations to enable Web Annotation on the web:

1. Web Annotation Data Model
2. Web Annotation Vocabulary
3. Web Annotation Protocol

Read an overview here:
https://hypothes.is/blog/annotation-is-now-a-web-standard/

W3's documentation here:
https://www.w3.org/annotation/

W3's announcement's for publication of a new recommendation:
https://www.w3.org/blog/news/archives/6156

Interactive infographic (may not be interactive in github issue)
https://www.w3.org/annotation/diagrams/annotation-architecture.svg