modal window for login and registration
Merge branch 'master' of https://github.com/vsomov/SchoolPortal.git

Conflicts:
	school-web/src/main/resources/messages_en.properties
	school-web/src/main/resources/messages_ru.properties
	school-web/src/main/resources/messages_ua.properties
	school-web/src/main/webapp/views/tiles/header.jsp