[FIX] product: more accurate name_search

First, name_search searches on default_code, then, if the limit is not reached, it searches on the product name
The results found from the default code search must be removed from the search domain when doing the search on the product name, to avoid having results already found by the search on the default_code

opw-618015
[FIX] point_of_sale: missing multi-company rule
Merge branch '7.0' of https://github.com/odoo/odoo into 7.0-win32