[IMP] product: Allow to search on variants barcode/ref from template
[IMP] product: Allow to search on variants barcode/ref from template

Purpose
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Be able to search on the internal reference & Barcodes of the product variants from the search on product.template
https://drive.google.com/a/odoo.com/file/d/0B0ITmdw6h3ZrZmw3Ym1LUzcwYU0/view?usp=drivesdk

ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo