DiGraphe Flip-text

This is a remix of dagobert_ch flip text.
My enhancements have been incorporated in his V3:
https://www.thingiverse.com/thing:6445271
This was a good "team work"!

It has various fillers in case the two words differ in length.
The fillers are spread at begin and end of the shorter name.
The fillers are stronger, in case the object size is reduced at slicing.
In case of combined name (like Jean-Francois) an heart filler appears.
The Openscad code uses the string functions of 16807user.