Begin to transform user into service

1. Define abstract service interfaces
2. Implemented interfaces for user (UserService)
3. Use UserService in user's REST CURD code

Also some minor bug fix:

Order of handler was incorrect. Listing of users would never run in
the old order.
Removed most entity type info from UserService

Half way to make UserService a generic entity service.
Separated User's REST from entity and database

1. Defined RestOnPat to handle REST interface (i.e. all
   json encode and decode issues.

2. Defined UpperIoService to handle generic CURD works of any
   database.

3. Defined PatRestHelper as a bridge between RestOnPat and
   UpperIoService.

4. Implements PatRestHelper with UserRest.
House keeping for upperio service

Organized upperio under service. Added some more comments.