[Telepathy] Icon Naming spec: add user-invisible

[Guillaume Desmottes]

Hi guys,

I'd like to propose to add 'user-invisible' to the list of status icons.
It would be used in Empathy's presence chooser instead of re-using
user-offline.
Most of IM clients (including Pidgin and Gajim) have a specific icon for
this status so I think that would make sense to have one in the naming
spec as well.

Note that this icon is already implemented in some icons theme,
including Ubuntu's humanity theme.

Attaching a patch adding this icon to the spec.

Thanks!


	G.