Fix segfault when source image is GIF
Merge branch 'fix-segfault-when-loading-gif' into develop
Merge branch 'develop' into release-0.19
Update minor version
Update configure script
Update README
Update manpage of img2sixel
Merge branch 'configure' into kmiya
Merge branch 'kmiya' into sandbox
Merge branch 'sandbox' into release-0.19
Bump version
Rebuild configure script
Merge branch 'release-0.19' into develop
Drop the preparation for SIMD enhancement
Drop unused posix_memalign stub function
Rebuild configure script
Merge branch 'develop' into configure