Release Lyon edition of protocol

[magnusbaeck]

Description

Once all issues for the Lyon milestone have been closed we should release a new protocol edition, Lyon.

Motivation

There have been a sufficient number of protocol changes to warrant a new edition. Editions make it easier to reason about sets of schema versions. Some Eiffel application may choose to only update their schemas to editions and ignore non-released event versions so being too restrictive about releasing editions creates delays.

Exemplification

N/A

Benefits

New features can be made generally available to users of tools that only update their schemas for new editions.

Possible Drawbacks

None.