Use email address as person display name.

When there are no better fields, use email address before using slug
directly.
New version of APM.
We have to clear our automatically added link if highlight is removed.

When highlight is removed, if there is a link to that highlight in
local annotation editor, which was put there automatically, and user
did not change anything there, we remove that now invalid link. If
there were changes, we do not do anything for now.
Use unicode for ellipsis.
Merge branch 'master' into email-invites