Configurable spool holder for the German RepRap Neo

The [customizable spool holder](http://www.thingiverse.com/thing:386483) of peka (which in turn was based on [the one](http://www.thingiverse.com/make:84189) from Luchador) had a too small gap to fit the wall of my RepRap Neo, when printed with Simplify3D.

So this spool holder has a second configurable parameter, the gap.