Add service v3 support for identity

simple rebase
rewrite help for create, remove choices
Added create/delete/list/show/set for service
Modified setup.py

Change-Id: I5ced0e214cc2f7fc70493c66b4381040ce8122fe
Add endpoint v3 functionality

simple rebase
integrated dolphm and dtroyer comments
Added create,list,delete,set,show endpoints
modified setup.py

Change-Id: Id6153db16db44130beb3b44a8e3e2f72e9a01e5f