[FIX]:Issue of add custome field on object
[DOC] Started workflow (technical) documentation.
[IMP] orm: expose a signal_xxx() method to call workflow.trg_validate().
[FIX] orm: call super in __getattr__.
[IMP] added create_workflow, delete_workflow,redirect_workflow as ORM methods.
[REF] model service: removed the unneeded object_service class.
[REF] services: somewhat clean use of openerp exceptions.
[REF] netrpc: removed.
[FIX] osv.object_service must be called osv.object_proxy.
[FIX] ir_property: correct import of orm module.
[REF] services: moved the db service to openerp.service.db.
[REF] services: moved the object service to openerp.service.model.
[REF] services: moved the common service to openerp.service.common.
[REF] services: moved the report service to openerp.service.report.
[REF] service: killed the ExportService concept.
[REF] service: workflow is not a service

- simply use openerp.workflow instead of the funky netsvc.LocalService
- the funky netsvc.LocalService is still available though
- all the methods are now simple function (the self was unnecessary)
[REF] netsvc: close_socket is only used in wsgi_server, so move it there.
[FIX] At the end of the database creation polling, None passwords are no more returned (for e.g. the portaluser).
[REF] service: A new openerp.service.rpc decorator is provided to replace the ExportService class.
[REF] object_proxy is no longer used by audittrail (which patches directly openerp.service.model).