Demoulding plate

[mpmf]

The generated demoulding plate can be improved in two ways:
1. Take into consideration the insideWallFlareWidth. Right now, if the insideWallFlareWidth is larger than the minInsideWallThickness the demoulding plate will not go through the hole.
2. With multiple walls, the generated demoulding plate will consist of multiple pieces that will have to be used as a puzzle. This pieces could be connected together to ease the usage of the demoulding plate.

I've already implemented a solution for these problems, but I'm not experienced in GitHub and, of course, have no permission to commit my changes. Also, I've never done a pull request and don't know if that's the right option. So, if it helps, I attach here my modified svg2cookiecutter.py (renamed to .txt so I can attach it), and an example of the generated demoulding plate.

svg2cookiecutter.py.txt