adding worker API in sketch form.
giant blob of work.  Middle layer almost done!  Added wrapper for ELE interface, test cases, filled in most (but not all) of the other cases.
Merge branch 'master' into auto-185-worker-api
Merge branch 'master' into auto-185-worker-api
ensuring that the entity ID is available where necessary.
Merge pull request #6 from rackerlabs/auto-185-worker-api

adding worker API (ready)