Fix production product deletion

This is a workaround for ProductionProductEditor. If we call self.cancel(), the
transaction will not be committed. If we call self.confirm(), it will, but
ProductComponentSlave.on_confirm will try to create ProductComponents for the
product that doesn't exist anymore (we removed them above), resulting in an
IntegrityError.

Change-Id: I781a9e117f067e130f28f8ea6a9313100e04a2e2
Add optical on PLUGINS list

Without this optical's data files will not be present on the .deb

Change-Id: Id65a10c56979cb0bd7c67cf23ea4ba3c95df7774