better error messages

[odanoburu]

- [ ] use http://hackage.haskell.org/package/formatting-6.3.7/docs/Formatting.html for string formatting

• use prettyprinter for string formatting
• use megaparsec's error reporting capabilities to show errors? or reduce them to our error reporting capabilities?
• more precise error locations
  • probably requires re-adding statements to the pipeline

[odanoburu]

should sorting errors show the correct sort order or just output the corrections to be made? 1 seems better for small numbers of elements, but we can't really sort and print all synsets in a file.. we currently implement 2 (albeit not perfectly)