Optimize demo/bitmaps All PNGs with FileOptimizer

This reduces file size, yet retains quality, so images load faster.

Stripped all meta data out(wasn't being used in any demos anyway), also
color profile, which fixes the libpng Incorrect sRGB color profile issue
with loading images with this profile.

NOTE: images.py needs rebuilt also, as py encoded images will retain
extra file size, color profiles, junk also.
NOTE: gifs/apngs should be optimized by hand as they contain animation
infos that need retained.