Implementations wiki page

Especially for people at I Annotate 16, but also everyone, please help fill
out a list of implementations of the specification in our wiki:

  https://www.w3.org/annotation/wiki/Implementations

[If there's already a page for this, I didn't find it -- only the old list
of pre-WD protocol systems]

Rob

-- 
Rob Sanderson
Semantic Architect
The Getty Trust
Los Angeles, CA 90049