moved copyValuesIntoSession and isContentEditable functions into the utility class. in editActivity, the state of the flags are added into the session,
new method implementations for addUser and addSession, updated code to match the new implementations of ToolSessionManager and ToolContentManager. Accoutns for the ToolException and DataMissingException which may be thrown
in remove* or retrieve* methods, added few extra steps so that it detachs the object from parents before persisting the changes to database. also new methods for access to user