RFR 8077102: dns_lookup_realm should be false by default

[Weijun Wang]

Hi All

Please take a look at
   http://cr.openjdk.java.net/~weijun/8077102/webrev.00/

Before this fix, dns_lookup_realm true is by default. This is not 
consistent with other krb5 vendors. It also leads to lot of time waste 
when Kerberos 5 is not configured at all.

The no-krb5.conf test case in ConfPlusProp.java is removed because with 
dns_lookup_kdc still being true by default, the test can timeout on some 
systems.

Thanks
Max