This filter is identical to ngSanitize's linky but instead of
sanitizing text which isn't linkified in the addText function,
it doesn't.

Remove org.matrix.custom.text.html event type and replace it with 'format' and 'formatted_body' keys on m.text messages

This format will remain undocumented as it is not yet suitable for
introduction into the specification.

Make sure to return an empty JSON object ({}) from presence PUT/POST requests rather than an empty string ("") because most deserialisers won't like the latter

SYN-103: Ignore the 'origin' key in received EDUs. Instead take the origin from the transaction itself

Server2server signing

Conflicts:
	synapse/app/homeserver.py

Clarify that room alias domain names will be server-scoped; nonlocal edi...

Clarify that room alias domain names will be server-scoped; nonlocal edits are unliekly to work but nonlocal lookups will

Outline and describe the keys from the initial sync API. Hide room-scoped
initial sync API for now as it is not implemented and needs more thought before
it can be specced.