Customizable Better Temperature Tower

This is a remix of the former [Better Temperature Tower][BTT] by [Thump2010][Thump2010] in OpenSCAD, fully customizable in temperature steps and range. A generic post-processor script is included - it works on any of the towers "automagically" as long as you set proper initial temperature in the filament settings, and slice at 0.2mm.

The eventual plan for the temperature customizer to extract the settings from the sliced tower (via embedded printed marks).

The generic layer temperature post-processor script for the [Better Temperature Tower][BTT] operates on the G-code generated by Slic3r.

By default, it starts with the printing temperature set in the Filament settings, then decrements it by 5 degrees C for each block of the tower. Its default settings work with any of the [Better Temperature Tower][BTT] models printed at 0.2mm layer height.

It is a more generic and compact replacement for the "tempTowerScript" family of scripts included in the [Better Temperature Tower][BT