Implement feeder (Just a trying version)

 + Create UI to create email source 
  -> Done: Created simple UI 
  -> TODO: continue creating UI
 + Create UI to create source fetcher
  -> Done: Created UI to create source fetcher
  -> TODO: continue creating UI
 + Fetcher handler
  -> Done:
      - Implemented simple job (recurrence base on interval time)
      - Implemented email fetcher with hardcode-config (just try to get
mail-attachment)
  -> TODO:
      - Improve email fetcher with dynamic config
      - Implement shared folder fetcher
      - Create service classes to handle fetching (now just try in job
class)
      - Implement complex job (recurrence base on day, date, month...)
      - Create fetcher job monitor UI
      - Implement fecher job monitor services (or handling classes)
      - Create UI to show news feed (grouping by source)
      - Implement  news feed handling classes

Change-Id: Ic644d551a63baf18583094cc24d33ee334630462