Share subsytem cert in shared tomcat instances
    
    In shared tomcat instances, we need to share the subsystem cert and
    not create a new one for each additional subsystem added to the instance.
    In addtion, if the instances share the same database, then only one
    pkidebuser should be created with the relevant subsystem cert and seeAlso
    attribute.
    
    Ticket 893
Please review, 
Thanks, 
Ade