GEOMESA-446 Wire up TDI via WPS

The only issue I know of is that the TDI process must be ran with xml as the output type currently. json does not work. Currently, we embed the json timeseries inside of the xml output (unless there is a query hint specifying to return an encoded time series object rather than the timeseries in json form).
would be nice to have consistency with the static vals here...i think scala recommends upper-case camel case for constants...

http://docs.scala-lang.org/style/naming-conventions.html#values_variable_and_methods

zeropoint and geomFactory are different from INTERVAL_KEY, etc.