Merge branch 'release'
Improve the color sampling method for makeing adaptive palette
Merge branch 'master' into feature-support-output-macro
Initial implementation for --use-macro option
Add --ignore-delay option
Add some descriptions for new options to documents
Bump version
Merge branch 'feature-load-gif-animation' into release-0.25
Merge branch 'feature-support-output-macro' into release-0.25
Merge branch 'release-0.25' into release