Orm refactoring. No more need for suffix __obj to get rel field

 - Record objects now behaves more like browse_record in OpenERP.
   No more need in suffix '__obj' to get related fields as records.
   They will be automaticaly converted to Record objects.
 - __getattribute___ in most cases changed to __getattr__
 - Record._name property that returns result of name_get method for this record
 - Objec.columns info refactored to use fields_get method to get list of fields for an object