Diaspora: Protocol enhancements

[annando]

There are still open tasks, so that the Diaspora protocol implementation can reach 100%. See here: http://diaspora.github.io/diaspora_federation/index.html

In difference to #4230 these are points that should be easier to implement.

• Editable posts. See issue Editable entities diaspora/diaspora_federation#94
• Private conversations with multiple contacts
• Process incoming events (Sending is currently not implemented in Diaspora)
• Process incoming event participation (Sending is currently not implemented in Diaspora)

[annando]

It doesn't seem as if Diaspora is implementing the events. Multiple recipients in private conversations are still a thing, but they will be solved when the mail part is reworked. (which will be done at some time in the future).