Fixed compilation by testing with spouse example

- Importing default env variables from skeleton-env.sh
- Fixed hocon2json to support multiple fallbacks
CSV parsing for supporting common dumps from postgres

- Using something like `psql dbname -c "COPY (select id,words,pos,ner,lemma from sentence limit 100) TO STDOUT WITH CSV HEADER"`.
- Also added a sample sentences with nlp tags.
Improved GUI frontend build regarding JS sourcemaps