Pub/sub & fuzzing

• Updated to uWebSockets v0.16.0
  • New efficient MQTT-like pub/sub base support, optimized for latency and performance
  • Project is now continuously fuzzed by Google OSS-Fuzz under three sanitizers with a coverage of 80-90%
    • Big deal for security; most hardened release so far
• Fixes some default WebSocket settings, defaults are now sane.