Allow check of a product stock on another branch

Included a dialog to search the stock of a product on all other
branches. For instance, if the local stock of a product is empty, the sales
person can check witch other branch has it in stock.

Change-Id: I597fc86c742bb49c65c16b156b3b7b06f1277bb4
fixes: http://bugs.async.com.br/show_bug.cgi?id=5514