Worker waits for queue to empty before refresh

- But that required a little bit of revamping
- This does NOT add batch capability. I'm not sure that's necessary
- task_server initialize now has option for turn off serialization
  during testing
- TaskEngine.connected? now exists, is true after it has connected to
  google and refreshed the tasklists
- task_server.working? is now actually functional. Apparently it was not
  previously. This works by returning "run" if there's a refresh
  pending, "sleep" otherwise.
- Added test tasks to Rakefile
- Cleaned up a lot of code to match syntax standards
Merge branches 'master' and 'add_batch_process'