Changed tab menu name and implemented checkbox

Change the tab menu name from playlink to security
Added a query for the visibility of listentries
Added public attribute to codeexample
Changed the query to select public from codeex.
Started hanges towards goal

Missing parts that updates the database and sets the checkbox to checked
if the current example is public. Check returned funciton?
The checkbox now updates the database

Fixed the problem where the database doesn’t get updated when clicking
the checkbox
The checkbox now gets data from database

The checkbox is now drawn based on the value of public
Added redirect when not logged in

User will be redirected when not logged in and trying to access a
private codeexample
Added an alertbox when access is denied
Merge pull request #316 from HGustavs/codeviewer-feature-security-#291

Codeviewer feature security #291