GEOMESA-234 using lexicoders for secondary index values

* Using mango lexicoders for primitive types
* Moving some encoding/decoding logic into more consistent locations
* Updating attribute strategies for querying with lexicoders
There's some discussion on it [here](http://osgeo-org.1560.x6.nabble.com/temporal-improvements-to-cql-parsing-td5037613.html) but it sounds like it should be supported based on that...