cmd/server: introduce sentry

Merge pull request #4 from zllovesuki/xor

buffer: use libp2p buffer pool implementation as global buffer pool with

8k aligned

server/gossip: reconnect to dropped peers

dep: use go 1.16 go.mod format and update dependencies

profiler: collect peer latency and tunnel types

gateway: reduce buffer to 16kb; reduce conn counts per host

server: more debug logging; invoke remotePeer regardless from active …

…or passive detection

README: updated to reflect additional CLI usage;

CI: add freebsd/amd64 targets

cmd/server: handle empty NegotiatedProtocol with gateway