add UserGroup preview page
add JSP functionality to modify add User to UserGroup, also controller to handle AJAX add/delete
add BO and JSP functionality to add UserGroup which User belongs, also controller to handle AJAX add/delete
add CSS classes blue and grey
change HTML table id using dataTables to use more unified version
add generator for new userGroup - student class
setup contact and about us pages
add them to security permitAll
add them as non controller views in webmvc
add links in footer
remove old links from tp menu
small fix: add error pages to security permitAll
remove examples: DTO, Controller, JSP, webmessages