C++: Shorter main() and less arguments for some functions

[t-mat]

• Create worker() instead of lambda[]()
  • I've moved g, a, b, c, ar, orig0 into the worker() for readability. It increase amout of calculation but negligible.
• Create clamp() instead of clamp[]()
• Modify tracer()'s argument and result type
  • Now tracer() just return the value, it will not modify the references.
• Introduce AAA style
  • Some initializer are still traditional style for compatibility reason.

[kidoman]

Awesome...

I had tried my hand at moving the lambda into a worker but it required too many things to go global, and had given up

:+1: