Errors when there are no paths

[simoncozens]

Here's the logic leading up to line 460:

            closestPathTime = None
            dist = 100000
            for path in layer.paths:
                # stuff
            n = math.floor(closestPathTime)

To avoid spamming the error log, you want something like:

            if not closestPathTime:
                return

in there.

[RafalBuchner]

Thanks Simon, I will look into that

[simoncozens]

Merged with #6.