RethinkDB 2.3 handshake V1.0 implementation

[maxp]

Connect to RethinkDB failed when host configured with user permissions.

Links:

• https://rethinkdb.com/docs/writing-drivers/
• https://github.com/rethinkdb/rethinkdb/blob/next/drivers/java/src/main/java/com/rethinkdb/net/Handshake.java

Some workaround: Use admin password in 'auth-key' connect parameter.