Updated lazy loader. The new version should be slightly more efficient on pages that contain many embeds.
Added support for GiPHY.
Added an add-on option to use a native player for the following embeds: Gfycat, GiPHY, Gifs.com.
Added an option to disable auto-embedding links on a per-site basis. If "Do not auto-embed links from this site" is checked when editing a media site, URLs from this site will remain as text links. Users can still embed third-party content by using the "Insert media" tool in the editor. This option is currently only available for media sites that belong to this add-on but may be extended to other media sites in a future version.
Some YouTube videos impose restrictions on which websites are allowed to embed them. This appears to be done by checking the content of the Referer header and/or accessing the iframe's parent. Because this add-on loads videos dynamically, some browsers such as Safari anonymize the origin of the request. In response, YouTube may refuse to serve the video and display a "Video unavailable" error instead. As a workaround, an option to use YouTube's default embed as been added. It will disable the lazy-loader and the miniplayer and it will allow YouTube to gather info about the parent webpage.
TL;DR: if YouTube videos don't load on Safari, check the "Use the default YouTube embed" option. Otherwise, don't.