Metacat

Added license terms to source code files, and cleaned up some javadoc
documentation in a few places.

Fixed problem with AuthInterface, AuthLdap, and AuthMcat where the
sigantures of the methods of these classes were not in agreement, which was
causing AuthLdap to no longer compile. Changed parameter signatures so that
the 'user' parameter is used consistently in all of the methods.

AuthMcat
- new class for authentication through MCA; implements AuthInterface
AuthSession
- assigning HttpSession obj only after successful athentication;
- cleared isAuthenticated field - not needed
- cleared invalidate() method - not needed
AuthInterface...

merge AUTH_LDAP to the main branch