Add scraper for Groupees.com

- Only scrapes entries with direct download links rather than keys to be
  redeemed on stores like Steam and ShinyLoot.
- Thanks to a quirk of the Groupees markup (games get a dropdown even if
  they only have one download while albums don't), only imports games
- No thanks to how Groupees uses AJAX, only works in bundle view
  and only on one bundle at a time.
Consistent colon spacing enforced by coffeelint
Enforce more existing conventions in coffeelint

(Unix line endings and omitting parens when defining functions which
take no arguments)
Enforce more existing conventions in coffee-jshint

- Capitalize all constructor function names
- Forbid arguments.caller and arguments.callee
- Never use "new" when calling a function purely for its side-effects