Hacky "support" for Renomination

This is a feature libwebrtc supports, that's barely standardized.
But if a client uses it, then it uses an alternative attribute for
nomination, and the value of this attribute is taken as a monotonically
increasing number, telling us to choose whichever option they nominated
"most recently", ignoring priority.

Since it's an alternative attribute, if we don't understand it then we
think the controlling side hasn't nominated anything.
So it's a bigger change to actually implement the storage of nomination
counter and use that instead of priority.
But if we just treat it as a normal "USE-CANDIDATE"... then it should at
least work better than nothing.

I'm hoping the other side will be tolerant to our limited understanding
of nomination.

Set Longer STUN Timeout

We were having an issue with outbound Jingle calls where it would fail
to establish a connection.

It appeared to be a bug in pjproject, specifically that they don't
retrigger failed triggered checks, and the call receiver started sending
checks before the call initiator (because they receive that info on call
acceptance), so there was plenty of time for things to fail before we
even had a chance.

This does not fix that bug, but by extending the window of time it
retries before declaring failure, we can step around it a little.

Update autoconf files for pjproject

Last-Update: 2018-12-21

config.guess and config.sub for pjproject are six years old, this
makes the build FTBFS on newer architectures like ppc64el.

Unfortunately the sources are only unpacked during the toplevel
./configure run, so we cannot solve this with dh_autoreconf

Gbp-Pq: Name autoreconf-pjproject

Import asterisk_16.2.1~dfsg.orig.tar.xz

[dgit import orig asterisk_16.2.1~dfsg.orig.tar.xz]