For ENG-5048, fix a bug in legacy export client where it would always reconnect on catalog update
Set longer TTL for Java DNS caching policy.

Successful DNS lookups will cache for 5 minutes.
Unsuccessful lookups will cache for 1 hour.
Add support for asynchronous/synchronous DNS lookups and rejigger hostname strings to always include the ip
For ENG-5048, was missing the enum, also renamed the enum
For ENG-5048, add missing license
For ENG-5048, fix test bug
Add a log statement to make it possible to see slow/broken DNS
For ENG-5048, clean up debug log message basd on Ning's feedback
Merge pull request #702 from VoltDB/ENG-5048

Eng 5048 Make a few reverse DNS enhancements and fix a bug related to legacy export and catalog update