Ditching mandatory TLS

[Drew DeVault]

Unpopular opinion time: Gemini should not have mandatory TLS.

- TLS is not conveinent for local development
- TLS is inherently dependent on a centralized oligarchy of CAs
- Baking TLS into the protocol is going to be a bad look when The Next
  TLS comes out
- Some alternative modes of internet access have built-in encryption
  guarantees: yggdrasil, cjdns, Tor; and for these adding TLS is
  redundant (and arguably worse)