[editing] list all required beforeEdit/Edit events (#79)

At the end of the F2F we found out that Safari has a built-in edit menu to give access to a number of richtext styling commands. We need both a way to turn that menu off (by means of an attribute or otherwise), and we need to list all those edit commands as (before)Edit events. Other browsers may want to hook into those events, even if they don't have a similar menu (ctrl+b -> bold, etc.).

Also, we need to list the editing events typically supported by Microsoft and add them to the events list if they are not covered yet.

@rniwa has promised to provide such a list within a month.

---
Reply to this email directly or view it on GitHub:
https://github.com/w3c/editing/issues/79