Remove "s" on meters when only 1 meter

[terracoda]

Item 3 from #215 (comment)

I found an "s" on meters when centers were 1 meter apart.
Can you add logic to remove the "s" in that case?

[terracoda]

Adding screen shot with VO text

[zepumph]

This was a small change in common code, which I like. I will apply to a few other spots too, is that alright? For example the "centers exactly {{distance}} {{unit}}" in the screen summary:

Does this feel good to you?

[terracoda]

Yes, that looks great! Thanks for finding and fixing these other spots.