New version of JDBC_PING. Named JDBC_PING2 because of schema changes.

The new schema will be more legible:
address (PK) | name | cluster | IP address | port | coord

The other changes include

• Code refactoring (code was written in 2010, with small changes after that). E.g. use of try() statements with AutoCloseable
• Perhaps stored procedures when feasible. Example: insert-if-absent
• Optimized configurations for the most frequently used DBs, including optimized zombie handling
  • E.g. GMS.join_timeout , GMS.max_join_attempts
• Probe support: e.g. managed operation to dump table contents
• Testing / junit code
• Better documentation

Upgrading from JDBC_PING -> JDBC_PING2

When upgrading, both protocols can be in the same stack (they will use different tables). Once JDBC_PING2 has all the data, the old version can be removed