User and Role now implement the \Serializable interface and implement the serialize() and unserialize() methods using json_encode and json_decode as the serialization algorithm. This is a work-around for a PHP 5.4 serialization bug.
Changed DOCTYPE to HTML5.
Adding new PubMed references now works. Big progress. Still need to do some clean-up, though.
Now using Jonas Rask Design Free Icons
Now using Jonas Rask Design Free Icons
Added delete-icon to css and partially to javascript.