Customizable Toothpaste Squeezer

This is the 105th design for a [toothpaste_squeezer](https://www.thingiverse.com/tag:toothpaste_squeezer).
In its form it is a modification of [this thing](https://www.thingiverse.com/thing:1147252). But on the one hand that thing does not print perfectly (especially at the so-called "lock feature") and on the other hand it can not be used with thick / awkward fingers.
Because I want to produce a copy for my father, it will be used with just such fingers - and it should survive.

This version is sturdy and can be operated with thick fingers.
Furthermore, it is parameterized and can be adapted to individual needs with the **Customizer**. And if something goes wrong with the Customizer (again!), the SCAD file loads easily in OpenSCAD 2015.03-2 as well as in 2018.11.24.nightly.