new role: admin
redirect to previous page after user editing
Merge remote-tracking branch 'origin/master'

Conflicts:
	src/main/java/ru/hse/esadykov/controller/UsersController.java
	src/main/webapp/WEB-INF/jsp/navigation.jsp
	src/main/webapp/WEB-INF/jsp/users.jsp
merge
Merge remote-tracking branch 'origin/master'