To Add stb Library

This library suite contains functions in self-contained files
for processing images, fonts, etc. making it easier to convert
to benchmarks for our use because each file is small and self contained
(unlike standard libraries such as libjpeg, libpng, etc.)

https://github.com/nothings/stb

Of course we still need to develop the harnesses/drivers or
convert floats to ints.
