Please allow pause AND filament change on same layer.

[hexsmith]

Title says it all. I want to be able to set a pause before a layer begins, so that I can change filament manually, then when it resumes, I want it to print using the settings for the new material. I can set the filament on the layer before or the layer after a pause, but I cannot apply them at the same time. I assume this is a trivial addition, so I'm not labeling it an "idea" but rather just a minor dev change.