Embed bare image links

Converts bare image links inserted in the post content into HTML tagged images, so turns links into visible images. Only applies into image links not tagged by the user. Useful for regular and bbpress instalaltions, to make easier for users inserting images just by posting a link to the image.

Extremely light, only computes when a user saves content, and just executes a light checking. It doesn’t run when readers access the blog.