the bugs of duplicating bom

[mike]

 When I select a product's bom, and click the "duplicate". I find that whether I click the "save" or click the "discard"，openerp always create the copy of sub-boms， you will see a lot of sub-bom's copy when you click "Bill of Material Components".

I think that the purpose of duplicating bom is just get copy of bom struct，and we do not need create copy of sub-bom automatically.