SPA: replace the DummyWorker by a real Worker
Fix jshint errors
Fix tests
set required NODE_ENV variable
Merge pull request #253 from tOkeshu/subworker-migration

Subworker migration
Merge pull request #254 from rhelmer/readme-missing-node_env

set required NODE_ENV variable
Fix typo in passing the database version to indexedDB.open to fix running in FF 25
Remove now redundant import of dummy_worker.js. r=tOkeshu over irc