Customizable stereographic projection revised

Revised version of http://www.thingiverse.com/thing:294899
Thanks to henrysegs tip the projection of the border region will now be much clearer. Wall thickness can be higher now without losing detail, all other instructions of the first version still apply.

Edit: Minor bug with the outer borders fixed. This version now also uses 75x75 pixels, as 150x150 doesn't work with the customizer.

Be sure to remove horizontal pixels, as described in the original thing.
If you need bigger versions you can do it locally with OpenScad and this script: http://jsfiddle.net/threonin/3j2c2pwe/