support PGM and PPM formats
treat vertical tab and form feed characters as whitespace
Merge branch 'master' of https://github.com/kennethdmiller3/stb
Merge branch 'master' of https://github.com/nothings/stb
Merge branch 'master' of https://github.com/nothings/stb
Merge branch 'master' of https://github.com/nothings/stb
Merge branch 'master' of https://github.com/kennethdmiller3/stb
Merge branch 'master' of https://github.com/nothings/stb
Merge branch 'working' of https://github.com/nothings/stb
Merge branch 'master' of https://github.com/nothings/stb
Merge branch 'master' of https://github.com/nothings/stb
Merge branch 'master' of https://github.com/kennethdmiller3/stb
Merge branch 'master' of https://github.com/nothings/stb
finalize scalar YCbCr conversion back-ported from SSE version;
add missing STBIDEFs to a few functions;
update documentation with full 1.49 info even though most isn't implemented yet
STBI_MALLOC etc.
some documentation cleanup
Merge branch 'master' of https://github.com/kennethdmiller3/stb into ppm
PNM cleanup
fix a few old error messages
tweak release docs
tweak credits
tweak revision history
remove trailing whitespace
in progress progressive stuff
fix non-progressive jpegs (had commented out a line accidentally);
fix long-standing bug where gifs were just broken AFAICT