v0.3.1

[thammegowda]

• Add support for recipes; list-recipe get-recipe subcommands added
• add support for viewing stats of dataset; words, chars, segs
• FIX URL for UN dev and test sets (source was updated so we updated too)
• Multilingual experiment support; ISO 639-3 code mul implies multilingual; e.g. mul-eng or eng-mul
• --dev accepts multiple datasets, and merges them (useful for multilingual experiments)
• tar files are extracted before reading (performance improvements) Closes #78
• setup.py: version and descriptions accessed via regex