Merge branch 'pp'
Linting
Merge pull request #1 from saitoha/fix-for-1bpp-png

Experimental support for 1bpp PNG
Propagate the result of convert_to_sixel and return correct exit status
code
Don't use stdint.h for old compilers
Minor fix
Drop unused function, GetColIdx
Style fix
Add error handling, and change the signature of LibSixel_LSImageToSixel
Bump version
Rebuild
Minor fix
Add some compatibility options to LSOutputContext structure
Minor fix
Minor fix
Merge branch 'develop' of https://github.com/saitoha/libsixel into develop

Conflicts:
	converters/quant.c
Merge branch 'develop' into feature-8bit-option

Conflicts:
	src/tosixel.c
Fix a typo (reported by @arakiken)
Implement 7bit/8bit mode
Update version