Laundry list of inter-peer wire protocol changes

The developer of inter-node protocol, Rusty, is trying to finalize the 1.0 version and has listed some changes or proposals he's aware of in a recent email. The changes include direct wire format stuff like using Protobufs vs open-coded structures, adding length prefix for initial key exchange, and length prefix for other packets. For HTLC pipelining, Rusty suggests supporting multiple in-flight HTLC negotiations but with some complexity. To add an HTLC abort stage, he proposes allowing the initiator to abort any time before revocation exchange. For version bits, he suggests exchanging two sets of version bits after key setup, one for compulsory features and one for optional features. In terms of wire protocol crypto, Rusty proposes using Crypto AES/HMAC-SHA256 or Chacha20/Poly1305, and a separate encoding stream for packet lengths. He also discusses other miscellaneous topics such as shachain vs elkrem, anchor tx renegotiation, R value vs keypair, and multi-sig txs. Rusty admits that there may be other changes he missed and asks for input from others. The links provided throughout the email provide additional information on each topic.