Supply custom server

[jasonkuhrt]

Perceived Problem

• there is no way to interop with servers other than express

Ideas / Proposed Solution(s)

• accept return value from function
• function must return an object with
  • a property to support add to context calls
  • a property for start
  • a property for stop
• treat as escape hatch, user should have to opt into this
  • log a warning in dev, fatal in prod
  • opt in via settings.change({ escapeHatches: { customServer: true } }) ??

Related Issues

• Server System #295