Updated cilogon signer to include the last round of changes - most
functionality now works except service certificate.
Refactored some functionality on isIssuedX509Cert on CertificateManager.
Renamed Certificate to CertificateBase to avoid conflict with
java.security.cert.Certificate.
Made user cert pkcs12 download to not output broken pkcs12 file if it
fails to create pkcs12 object.
Removec cert. status indicator to simplify UI changes made to allow
certificate revocation.