Mk3 renderscript

[mariusvw]

Script to automatic render all files in one batch.

It would be nice if someone can provide the right OpenSCAD settings used at Prusa

[triplepoint]

I think this is a great idea, though I think unless the changes to the .scad files were necessary for the script to run, you should remove those changes for this PR, so that we're not combining multiple independent changes.

The big hurdle here will be getting Prusa Research to change their release process to use this script instead of their current undocumented process. This is related to #94 I filed in August which hasn't seen any comment at all from Prusa Research.

But to repeat - I think this is a great idea, and it would be great if official release builds started using it to build their release tarballs.

[mariusvw]

See #108