renamed to user management
changed sidebar back to original

issues fixed due to complete redesign of sidebar architecture
introduced new SESSION variable for userrole to identify corresponding
sidebar
also inroduced SESSION variable for pressed button to track section user
is in
added unset command for certain SESSION variables

prevents the website to jump back to Index.php if the user loggs of only
new page due to new navigation bar button
change back to original sidebar
new information on main Admin screen due to new navigation options
redirect to login screen if user tries to access this page without login or necessary rights
style adjustments for navigaton and loggedOnInfo
new file holding the advanced navigation
handling of new variables btn and userrole
markup changes
new buttons added, registry btn disapears if user is already logged on
reduced info on first main screen
include redirect if user tries to access areas he is not supposed to due to his role
no longer needed as consolidated to on PSD file