-SQL dump with new fields (+Extras.type, -Extras.bool_garage,
+Proposals.duplex_side)
-New logic:
-> Double house (duplex): Now, you can select which part of the duplex
(if the house is a duplex) in edit_house; and it is shown in Prop->view
-> Extras that make the house standalone, are taken into account in
Prop->view.
-> Basement: If there is a basement, Prop->view does not show basement
related pictures.

-Some fixes to fit the new logic with the old one.