Slug for speaker profile links

[rixx]

1. Use the username (current implementation, can't do that, it's a data leak).
2. Calculate a slug at registration time (if it doesn't change with name changes: it's a data leak. If it does change with name changes: produces dead links)
3. Don't provide a speaker profile page, just link other talks on talk pages (probably not as bad as it sounds?)

Input appreciated, @raphaelm.

[raphaelm]

I think either (2) with a random slug like for submissions or (3) are fine

[rixx]

I'm not even sure what would go on a speaker page except a short bio and links to conference talks, which is so little that it does not quite require a page of its own. OTOH speakers and folks in general might expect speaker pages. Hm.

[rixx]

We'll stick with (3) and provide a good speaker bio on talk pages.