Eref redesign di Steve Dekart

The plugin helps improve the outdated interface for eref.vts.su.ac.rs. It reworks both CSS styles and entire pages. The plugin also includes:

* Adaptive for mobile phones
* Improved text readability
* Search for links in the text and format them into clickable links (E-tabla)
* Search the list of teachers and view information about them by clicking instead of hovering.