Since 2010-04-30 acts-as-taggable-on uses namespaces for their models. This patch is needed to run the retro_blog extension with recent versions of acts-as-taggable-on. This fixes http://retrospectiva.org/tickets/840
If avatar uses http to get gravatar-images, browsers will complain when retrospectiva runs in a secured (https) environment. This patch adds an option to the gravatar method and it's default value depends on the site_url setting. If retrospectiva runs within a https server, it will use secure connection, non-secure connection otherwise.