Added Conds interface

Added interface to represent conditions in a query.
Also the basic implementation of it.
Update ListCond and Service interface

1. Added the new Conds as a parameter in BasicListCond.
2. Added method ListCond.GetCond so it can return generic query condition.
3. Added method ListCond.GetMap so it can work better with upperio.
4. Added Service.Search as a generic listing method.
Implement the new Service interface in upperio

Modified upperio.Service to implement the new interface.
Also various change to upperio.Service struct itself.