fix bug

  db.objectStoreNames.contains not support array
  validateStoreNames and test-spec not work correctly

tested, not push the generated files, and not updated the version 

By the way , 
1. compile coffee file to /angular-indexed-db.js (not the same dir of coffee file ) is not convenient to debug.
2. what's the '"grunt-haml' for , it make some trouble to install ( on windows )

Function arrow (->) must be spaced properly