videomixer-like plugin with 1.0

[Douglas Bagnall]

In a confused state I wrote:
> I think I need to write a plugin that externally looks like videomixer
> (i.e., with a single video source, and multiple request video sinks),
> but whose internal magic is quite different.
> 
> As far as I can tell, there isn't a base class for many-to-one video
> elements, so I am wondering if any of the following approaches seems
> sensible:
 
> 1. Modify videomixer.[ch]. It is a bit daunting because I haven't yet
> worked out which bits are mixer specific, and which bits are the
> many-to-one infrastructure.

Well now I see there are no such files. Perhaps I opened them in the
editor before doing the git pull, or something. So I will use
videomixer2 as a base.  Sorry for the noise.

Douglas