the Icon and Button APIs already escape attributes, fixes #1797

app/controllers/course/ilias_interface.php

app/views/admin/course_wizard_steps/index.php

app/views/admin/ilias_interface/index.php

app/views/admin/lti/index.php

app/views/admin/specification/index.php

app/views/admin/user/show_user_courses.php

app/views/contact/index.php

app/views/course/forum/area/add.php

app/views/course/forum/index/_threads.php

app/views/course/ilias_interface/add_object.php

app/views/course/ilias_interface/index.php

app/views/course/ilias_interface/view_object.php

app/views/course/lti/index.php

app/views/course/members/accepted_list.php

app/views/course/members/add_dozent.php

app/views/course/members/add_member.php

app/views/course/members/add_tutor.php

app/views/course/members/autor_list.php

app/views/course/members/awaiting_list.php

app/views/course/members/dozent_list.php