Started implementing new auth module.
Implemented new dev auth, removed old auth.
Updated DJ to use fluent-ffmpeg 2.0.0-rc2.

Be sure to update fluent-ffmpeg to this version.
createTmpDir() now omits trailing slash.
Fixed artwork extraction function with new ffmpeg api.
Merge branch 'new-fluent-ffmpeg' into dev with updated fluent-ffmpeg.

Note: You must reinstall the fluent-ffmpeg@2.0.0-rc package at this point.
Removed concurrencyLimitor, readded async.js instead.

You must install async@0.9.0 at this point.
Fixed rejecting an entire song if it has no album art.
Incremented version to v1.3.2-alpha.
Merge branch 'dev' at v1.3.2-alpha.

Update packages.

Fixed:
  Won't reject an entire song if it has no album art.
  Removed flawed concurrencyLimiter code, reintroduced async.js for that.

Other:
  Updated to use fluent-ffmpeg 2.0.0-rc2.
  Refactored auth and dev-auth modules.