added missing 'static' property
added Controller, index.php and much more

everything is now accessible from one file (index.php),
the controller controls which Model and View is created,
templates are splitted into header, menu, content and footer,
View is now an abstract class not an interface and contains all methods
a new View must have
fix for last commit

a template file wasn’t commited properly
fix for error on publication page

when a publication with no key terms is shown there should not be any
error but an empty key term section instead