JS pagination refresh optimized
 Changes to be committed:
	modified:   school-service/src/main/java/school/service/GroupService.java
	modified:   school-service/src/main/java/school/service/implementation/GroupServiceImpl.java
	modified:   school-web/src/main/java/school/controller/ControllersUtil.java
	modified:   school-web/src/main/java/school/controller/GroupController.java
	modified:   school-web/src/main/java/school/controller/GroupEditController.java
	modified:   school-web/src/main/webapp/resources/css/course.css
	modified:   school-web/src/main/webapp/resources/css/group-edit.css
	modified:   school-web/src/main/webapp/resources/css/group.css
	new file:   school-web/src/main/webapp/resources/gif/spinner.gif
	modified:   school-web/src/main/webapp/resources/js/group-edit.js
	modified:   school-web/src/main/webapp/resources/js/utils/pagination.js
	modified:   school-web/src/main/webapp/views/groups/head-teacher-edit.jsp
	modified:   school-web/src/main/webapp/views/groups/head-teacher.jsp
	modified:   school-web/src/main/webapp/views/groups/student.jsp
	modified:   school-web/src/main/webapp/views/groups/teacher.jsp
	modified:   school-web/src/main/webapp/views/tiles/sidebar.jsp
Merge branch 'master' of https://github.com/vsomov/SchoolPortal

Conflicts:
	school-web/src/main/webapp/views/tiles/sidebar.jsp