The API was incorrectly assuming that all uses of the API were for a
course, and that the instanceid of the communication instance was a
course id. These assumptions are both entirely wrong.
The API is intended to support a range of uses including use at the
site, user, and activity levels.
Furthermore, if a group were to be used, then the instanceid should be
of that group's id, and therefore the contextid would need to be fetched
or that group's course instead.
The only solution here is to add a new contextid field to the table, and
implement it all parts of the API.
This is a brand new subsystem, plugin-type, and plugin. They are written
from the ground up by us. They should not contain any coding style
violations.
Michael Hawkins