#58 Better decoupling of database tables from JGuard JDBCManager

[chk]

Fact: it is hard to integrate existing database schemas to JGuard.
Reasons:
1.) the modelling of the database table after the two xml very complicate files JGuardUsersPrincipals.xml and jGuardPrincipalsPermissions.xml (complex design coupled with too little documentation!)
2.) the framework creates database tables with denormalized (redundant) information
Rational: for the adaptation of jGuard to existing databases containing login/user data it is necessary to have a better decoupling of the existing database tables and the jGuard framework for authentication data

Regards,
chk