Apply @uobikiemukot's patch (various pixel-format support)
https://gist.github.com/uobikiemukot/7adab29310caf0be6f7a
Swap bytes if depth == 2
Keep compatibility
Merge pull request #8 from saitoha/fix-segfault-with-introducing-various-pixformat

Keep compatibility
@uobikiemukot's patch in the conversation of #8
Merge branch 'feature-support-various-pixformat' of github.com:saitoha/libsixel into feature-support-various-pixformat
Merge branch 'master' into release
Merge branch 'master' into feature-support-various-pixformat

Conflicts:
	converters/img2sixel.c
	include/sixel.h.in
	src/tosixel.c
Merge branch 'hotfix-preventing-double-free' into feature-support-various-pixformat
Merge branch 'master' into release
Suppress gdk-pixbuf assersion on processing some GIF images, reported by
@ttdoda
Merge branch 'master' into fix-suppress-gdk-pixbuf-assersion
Merge branch 'master' into release
Merge branch 'fix-suppress-gdk-pixbuf-assersion' into release-1.2
Bump version
Fix wrong HLS-to-RGB conversion routine
Merge branch 'release-1.2'
Minor fix
Merge branch 'feature-libpng-integration' into release-1.3

Conflicts:
	configure
	configure.ac
Minor fix