Reviewed-by: mbalao

Reviewed-by: mbalao

Reviewed-by: valeriep

8147772: Update KerberosTicket to describe behavior if it has been destroyed and fix NullPointerExceptions
8163104: Unexpected NPE still possible on some Kerberos ticket calls
Reviewed-by: weijun

Reviewed-by: coffeys, weijun

Reviewed-by: darcy

Reviewed-by: darcy, weijun

Reviewed-by: mullan

Reviewed-by: alanb, iris, lmalvent, bristor, peterjones, darcy, wetmore