This change does not include the addition of VP9. We do that in a
separate pull request.
Changes:
* fix the video bug (video frames larger than 65KBytes) by sending full
frame length in alternate header field
* improve video frame reconstruction logic with slots
* configure video encoder and decoder to be multihtreaded
* set error resilience flags on video codec
* change encoder and decoder softdeadline
"All rights reserved" was incorrect. The project was licensed under GPL3,
which means a lot of rights are licensed to everybody in the world, i.e.
not reserved to the "Tox Project".
This removes the global logger (which by the way was deleted when the first tox
was killed, so other toxes would then stop logging). Various bits of the code
now carry a logger or pass it around. It's a bit less transparent now, but now
there is no need to have a global logger, and clients can decide what to log and
where.