Remove Qt dep from traced

[rburchell]

Rationale

Having minimal dependencies is good for running on "strange" systems if needed. Having minimal dependencies also means minimal chances of performance issues in unexpected places.

Broad plan

• Blocking socket I/O
• Thread per connection
  • (and possibly subsequently per chunk to process? memcpy the buffer out of shm, and release the chunk back ASAP, then process? Stretch goal, maybe a separate issue)