Merge origin/core into core

Conflicts:
	src/main/webapp/WEB-INF/views/page-not-found.jsp
	src/main/webapp/WEB-INF/views/topic-details.jsp
	src/main/webapp/WEB-INF/views/topic-list.jsp
	src/main/webapp/WEB-INF/views/training-delete.jsp
	src/main/webapp/WEB-INF/views/training-details.jsp