original paperclip source (I just copied it over). Ruby 1.8.7 provides a Tempfile that not only supports extensions, but avoids a bug where reusing the same filename to paperclip in succession (such as in a test) can result in missing file exceptions, since the tempfile is moved, another tempfile is created in the same location (same basename), then the first tempfile's finalizer triggers and remove the new tempfile that we are still working on.
changed using DataMapper::Property.required(true)
…y since dm-core depends on it.
…nt tested it directly yet
…ls as one about re-setting a constant