GEOMESA-494 GEOMESA-523 GEOMESA-525 Replace scopt with jcommander

* Replaced scopt with jCommander
* Refactored arguments into common classes
* logged to stderr instead of stdout to support redirecting of ouput (removed stdout flag) (GEOMESA-523)
* added "json" in addition to "geojson format"
* updated readme
* Bundled SLF4j with assembly (GEOMESA-525)
it would be nice to have that be part of the output format - gml2 vs gml3. I think that's how geoserver does it. Could be another ticket though.