"waiting for input" > open shouldn't let you open the same window twice

New idiot-proofing measure! In a pixel or IC run, if you open the new window so you can do the pixel/IC thing and then navigate back to the original Rodan window and hit open again, it opens a whole new version of that window instead of pulling the one you already opened. This is mostly problematic because what is done in one window doesn't transfer to the other.

This happened to me when I had multiple 'view' and input windows open and lost track of the IC window I already had open, opened another, finished it, closed it, but the other one was the main session (I suppose), and the progress was lost. ✨ idiot-proofing ✨ . I don't know how likely this is to happen to another person, but if it happened to me I figure I'll make a note of it just in case.