mostly javadoc update and bug fixes

javadoc added and updated to various classes
timed tasks added for regular maintainence
secure / insecure server name references set FC
fixed enrollConfirm 'no courseId' bug
close jdbc statements seperately from connections
added timestamp to enrollments
added comments table to db
added comment review page to dashboard

Signed-off-by: celynch <celynch@gmail.com>