[Galene] Simulcast support -- please test

[Juliusz Chroboczek <jch@irif.fr>]

Hi,

I've just pushed the "simulcast" branch to github, and I've deployed
a version of Galène with simulcast support at:

  https://galene.org:8444/

The instance on port 8443 is still running the stable 0.3 branch.

Simulcast is a technique where the sender sends multiple streams, at
different qualities, and the server decides, for each client, whether to
send the high- or the low-quality stream to the client.

Right now the selection is manual: you'll find a new box in the side menu
that allows you to choose whether to send multiple streams (the default is
"auto", which currently means yes except at the lowest bitrate), and new
choices in the "receive" box.  The plan is that ultimately the choice will
be automatic, depending on network conditions.

I need help with testing from people with Macs.  Please be so kind as to
verify that the instance on port 8444 work with both Safari and Safari for
iOS, and let me know if I've broken anything.

Thanks,

-- Juliusz