Remove dependancy on Sun's JNDI-DNS provider

Java Webstart now uses Sun's JNDI-DNS name service provider as the default on windows since b27 (see CR 6228306).

This was intorduced to fix a problem whereby webstart would appear to hang for long periods of time where ip address lookups were happening. These lookup issues are being addressed by CR 4084543 & 6205925. When these CR's are fixed the need for the JNDI-DNS provider should be removed.

Regardless of the above the JNDI-DNS provider is not a complete DNS resolver implementation and should not be used as the default. see comments section for specific problems.