scaffold-project.py: a --pin whose file the shape writes itself (spec, code, shape, any case, owner or not) or another --pin writes (openGlass and OpenGlass, or one product twice) is refused before anything is created, under --dry-run alike, so --pin spec@<sha> no longer plans and then makes three repositories to die in the materializer, and a repeated pin is no longer dropped without a word (#241) - #256