Update version number

Change byte casts in stb_image.h that intentionally truncate to do so explicitly for MSVC runtime check compatibility

Added comments for all stb_ functions since I'm
now using this program as an illustrative example
of the value of something like stb_ functions.

Conflicts:
	tests/stretch_test.dsp

Fix handling of iphone-procesed image to not accidentally appear corrupt (instead they just load wrong).
Add a proper testing path to image test