JSON output i200 added `--json` argument

http://gsd.uwaterloo.ca:8888/question/873/produce-instance-data-as-json
refactored IG Env to reduce duplication and nest IGArgs and ClaferEnv
bumped version to 0.3.3
added dependency on json-builder and string-conversions
split --addUidsAndTypes into --useUids and --addTypes. --json forces
--addUids