General note keeping file

Timings

This was done on a Windows 10 machine with an i5-3570k and 8GB ram. The target image is 640x360 with 64 samples per pixel.

-O3: ~74.50s -Ofast: ~78.66s ?????????? -Ofast & -march=native: ~70.20s -Ofast & -march=native & -fopenmp: ~23.45s