This change adapts pion/ice to use a new interface for most network
related operations. The interface was formerly a simple struct vnet.Net
which was originally intended to facilicate testing. By replacing it
with an interface we have greater flexibility and allow users to hook
into the networking stack by providing their own implementation of
the interface.
When machine's network interface have more than one ip address and
user don't want expose one of these ips to remote peer, interface
filter can't work in this case, so add a ip filter for that.
pion/webrtc@v3 will be trickle by default, so removing
support from here. Users can easily simulate non-trickle
by setting a OnICECandidate callback.
This just reduces the amount of things we need to test/worry about.
If we can't iterate host interfaces give a warning to the user.
Also don't bail early if a single interface fails, other interfaces
might still be in a good condition.
Resolvespion/ice#75
