Resolves: pki trac ticket #1638,2436,2443,2444,2446,2447,2449
    
    - PKI TRAC Ticket #1638 - Lightweight CAs: revoke certificate on CA deletion
      (ftweedal)
    - PKI TRAC Ticket #2436 - Dogtag 10.3.6: Miscellaneous Enhancements
      (edewata)
    - PKI TRAC Ticket #2443 - Prevent deletion of host CA's keys if LWCA entry
      deleted (ftweedal)
    - PKI TRAC Ticket #2444 - Authority entry without entryUSN is skipped even if
      USN plugin enabled (ftweedal)
    - PKI TRAC Ticket #2446 - pkispawn: make subject_dn defaults unique per
      instance name (for shared HSM) (cfu)
    - PKI TRAC Ticket #2447 - CertRequestInfo has incorrect URLs (vakwetu)
    - PKI TRAC Ticket #2449 - Unable to create system certificates in different
      tokens (edewata)