Floating point numbers shouldn't be localized in the JSON
Refactor HiveType

Move Type out of HiveType, in preparation for supporting parametric
types
Fix JDBC client hanging the JVM on shutdown

The IO pool was not specified for the HTTP client which caused the threads
to be created as non-daemon threads (which prevented the JVM from exiting).
Add option for double scheduling

Allows nodes to be selected multiple times during selection for a
particular stage