read_search method as implemented in Tryon, can save server roundtrip

Tryton made a smart one with their "read_search" method in trytond/model/modelstorage.py
It performs both a normal read but also supports a search domain on it. Actually even before knowing that Tryton made it we thought about it when we were doing some OOOR - OpenERP integration because we felt it was too bad to have some many extra server roundtrips just to do a search before a read. It does import when server latency is important, so I suggest you also implement it in OpenERP.