Allow upper floor trash#892

I had a small factory design that used the “Trash” hole to get rid of some unwanted pieces. The original design worked completely on the first floor, so I thought I could make things more efficient without wasting space by duplicating the factory on the floor above it. I assumed the trash would still work as long as the outputs for unwanted pieces end right above the trash holes. Sadly, this did not work. Trash holes can only be placed on the first floor, and machines on higher floors cannot “drop” their output into a trash hole.