Fix

[AlexDo1]

In this commit we removed grDevice from NAMESPACE because it prevented the package from installing successfully.

This will most likely break the plot functions in the package, so we can remove the dependency by replacing the usage in the plot functions or by making the package installable with grDevice (however?).

[JanWien]

Not sure if grDevices itself prevents the successful installation, or just "bringToTop", which is Windows-specific?

If the latter, it might be resolved by #5