fix errors of type 'Unsafe usage of new static', fixes #1245

lib/classes/I18N.php

lib/classes/Interactable.class.php

lib/classes/LicenseAvatar.php

lib/classes/MultiDimArrayObject.class.php

lib/classes/QuestionBox.php

lib/classes/QuickSearch.class.php

lib/classes/RangeConfig.class.php

lib/classes/WidgetContainer.php

lib/classes/forms/Form.php

lib/classes/forms/Input.php

lib/classes/helpbar/Helpbar.php

lib/classes/sidebar/Sidebar.php

lib/models/OERDownloadcounter.php

lib/models/OERHost.php

lib/models/SimpleORMap.class.php

lib/models/StudipNews.class.php

lib/models/Token.php