3.1.0

Changes

• Adds special handling of GIFs in srcset attributes to preserve animation.
• Makes internal srcset/sizes functions more consistent.
• Fixes a bug where functions hooked into tevkori_image_sizes_args were not firing.
• Fixes a bug where custom sizes attributes added via the post editor were being overwritten.
• Deprecates hook wp_get_attachment_image_sizes.
• Fixes a bug where the_post_thumbnail() would fail to add srcset/sizes attributes.
• Several improvements to internal inline documentation.
• Major improvements to function/hook documentation in readme.md after 3.0.0 changes.