Allow you to pass in a source building to the transfer products dialog to pre-seed options.
Split #update out into source_changed and destination_changed methods.
Fix issue in stored_products_list_store where precision was off, causing divide by zeroes. Whoops.
Change transfer_products_dialog to do all the heavy lifting.
 - Pop up a dialog asking how many of the given product to transfer.
Remove deprecated code.
Allow calling class to define parent window.
Fix crash when trying to transfer to a full destination.
A little bit of code cleanup.
Update TODO.