OpenSCadOutput writes numbers in scad-code using current culture

[donid]

When converting double-values to text, ".ToString()" uses the settings of the current culture that is configured in the operating system (or the current thread). A call to ".ToString(CultureInfo.InvariantCulture)" must be used instead. If I run the current code on a system with e.g. German culture settings and specify a radius of 5/2 it will generate this code: r=2,5 which obviously doesn't work, because commas are used to separate parameters.