Yggdrasil-based P2P demo (#1108)

* Initial work on Yggdrasil demo

* Muxing?

* Yamux

* Updates to yamux

* Updates

* Comments

* Update to use monolith stuff

* Update go.mod/go.sum

* Set defaults

* Tweaks

* Update yggdrasil

* Update config

* MarshalIndent

* Change default instance name/port

* add -peer switch

* gocyclo, for a change

* Determinate yamux roles

* Fix copyright notices

* Remove HTTP API checks as always false, remove unused topic

go.mod

@@ -3,6 +3,7 @@ module github.com/matrix-org/dendrite
 require (
 	github.com/Shopify/sarama v1.26.1
 	github.com/codahale/hdrhistogram v0.0.0-20161010025455-3a0bb77429bd // indirect
+	github.com/gologme/log v1.2.0
 	github.com/gorilla/mux v1.7.3
 	github.com/hashicorp/golang-lru v0.5.4
 	github.com/lib/pq v1.2.0
@@ -14,6 +15,7 @@ require (
 	github.com/libp2p/go-libp2p-kad-dht v0.5.0
 	github.com/libp2p/go-libp2p-pubsub v0.2.5
 	github.com/libp2p/go-libp2p-record v0.1.2
+	github.com/libp2p/go-yamux v1.3.7
 	github.com/matrix-org/dugong v0.0.0-20171220115018-ea0a4690a0d5
 	github.com/matrix-org/go-http-js-libp2p v0.0.0-20200518170932-783164aeeda4
 	github.com/matrix-org/go-sqlite3-js v0.0.0-20200522092705-bc8506ccbcf3
@@ -32,6 +34,7 @@ require (
 	github.com/uber-go/atomic v1.3.0 // indirect
 	github.com/uber/jaeger-client-go v2.15.0+incompatible
 	github.com/uber/jaeger-lib v1.5.0
+	github.com/yggdrasil-network/yggdrasil-go v0.3.15-0.20200530233943-aec82d7a391b
 	go.uber.org/atomic v1.4.0
 	golang.org/x/crypto v0.0.0-20200221231518-2aa609cf4a9d
 	gopkg.in/h2non/bimg.v1 v1.0.18