Merge pull request #11 from Asana/cofactor-20141124

Cofactor 20141124
Remove _teams/_projects/_tags/_users from Importer. No longer used and all state should be stored in DBs to facilitate resuming
Replace Cursor with BatchIterable, refactor forEachParallel to work with ES6-like iterables
Don't include Users with a deactived or missing DomainUser