Tweaked Photo Sweep Stand

The comments in http://www.thingiverse.com/thing:106568 mention a few problems with that version, and I had similar problems when I printed one, so I imported it into openscad (you'll need to download those original files to use the openscad source included with this thing) and produced this new version.

Uses 1.75mm filament as the pin instead of printing one. Adds some ribs to the area that clamps the paper to hold it better. Removes a feathered edge at the bottom that was too thin to print well.