Implementation should follow the following formal specification:
"title" and "content" data can be passed in raw, xhtml or rich format.
When we receive from a frontend a new/updated microblog item:
- keys "title" or "content" have to be escaped (disable HTML tags)
- keys "title_rich" or "content_rich" have to be converted from the current syntax to XHTML
- keys "title_xhtml" or "content_xhtml" have to be cleaned from unwanted XHTML content
Rules to deal with concurrent keys:
- existence of both "*_xhtml" and "*_rich" keys must raise an exception
- existence of both raw and ("*_xhtml" or "*_rich") is OK
As the storage always need raw data, if it is not given by the user it can be
extracted from the "*_rich" or "*_xhtml" data (remove the XHTML tags).
When a frontend wants to edit a blog post that contains XHTML title or content,
the conversion is made from XHTML to the current user-defined syntax.
- plugin text_syntaxes: added "text" syntax (using lxml)
