[FIX] orm: function/related fields with store != None should always use db-based search, regardless of fnct_search
[FIX] orm: function/related fields with store != None should always use db-based search, regardless of fnct_search

This reverts commit jvo@tinyerp.com-20100202150454-x9kne83yzkjciidw (1950) from v5
and it port to v6 with commit jvo@tinyerp.com-20100202150454-x9kne83yzkjciidw (1844.4.90) 
xrg/openerp-server,xrg/openerp-server