GEOMESA-254,269 Improving ingest in GeoMesa-tools

* Fixed up csv parser in SVIngest so that quotes are not required
  around geometry field (except for cases when WKT uses commas like polygons) 
* updated readme.
* Ingest command now splits up into sub-commands per format,  e.g. ingest csv | tsv | etc..
Oh!  Sorry I didn't see this before...  The flatten did raise a red flag... 

Since we are passing in the file line-by-line, we can ditch the flatten here, and then ....