git-svn-id: https://www.imagemagick.org/subversion/ImageMagick/trunk@16651 aa41f4f7-0bf4-0310-aa73-e5a19afd5a74
git-svn-id: https://www.imagemagick.org/subversion/ImageMagick/trunk@16653 aa41f4f7-0bf4-0310-aa73-e5a19afd5a74
Enabled sixel coder.

git-svn-id: https://www.imagemagick.org/subversion/ImageMagick/trunk@16656 aa41f4f7-0bf4-0310-aa73-e5a19afd5a74