LDEV-1633 added 'join' method to be called when adding a class of learners and staff to a lesson; fixed type error in 'delete' method; removed commented out code; call static constants from HttpServletRequest class, not instance.
For the 2.1 updatersThis copies adds any exisitng non defualt tool contexts from the database to the web.xmls of central monitoring and learning. It also updates the application.xml if the tool web project is not listed