Bump transport to v2.2.7

Revert "Cleanly close agent goroutines"

This reverts commit d8341e7.

Revert "Cleanly close agent goroutines"

This reverts commit 822108b.

Remove IPv6 ZoneID from ICE candidates (#704)

Link-local IPv6 addresses may have ZoneID attached at the end. It has
local meaning only and should not be send to other parties. This change
removes ZoneID from generated candidate string, and ignores ZoneID
when received candidate is parsed.

Remove IPv6 ZoneID from ICE candidates (#704) (#707)

Link-local IPv6 addresses may have ZoneID attached at the end. It has
local meaning only and should not be send to other parties. This change
removes ZoneID from generated candidate string, and ignores ZoneID
when received candidate is parsed.

Cleanly close agent goroutines

Cleanly close agent goroutines

Fix Callback ordering for ConnectionState (#702)

* Fix ConnectionState being reported out of order

Before we launched a goroutine to announce every ConnectionState change
to users. These could then be sent to the user out of order.

This commit adds a connectionStateNotifier. The connectionStateNotifier
delivers them sequentially to the user.

Resolves #624

* Use Notification Queue from 67cc918 more

Deliver Candidates and Selected CandidatePairs using the same queue.
This means that things are delivered in order and we don't have to worry
about blocking

---------

Co-authored-by: Sean DuBois <sean@siobud.com>

Add BindingRequestHandler

Allow the user to perform custom processing for inbound STUN Binding
requests. This allows users to do some of the following

* Log incoming Binding Requests for debugging
* Implement draft-thatcher-ice-renomination
* Implement custom CandidatePair switching logic

Resolves pion/webrtc#2539
Resolves pion/webrtc#2585
Resolves #623

Add BindingRequestHandler

Allow the user to perform custom processing for inbound STUN Binding
requests. This allows users to do some of the following

* Log incoming Binding Requests for debugging
* Implement draft-thatcher-ice-renomination
* Implement custom CandidatePair switching logic

Resolves pion/webrtc#2539
Resolves pion/webrtc#2585
Resolves #623