Verify Policy set is valid. Validity is defined as
- All KeyStore names should be defined starting with letters or '_' and then continuing with Alpha-Numeric characters, '-', '.' or '_'.
- If signedBy is specified then keystore is specified for both grants and permissions.
- That any keystore names used by grant or permission reference actual keystores.
- If target is null then actions is null.
@author Peter Donald
@version $Revision: 1.1 $ $Date: 2004/04/19 22:20:26 $