Adding visual call-outs for high order count vs. low order count

[pmaji]

Taken from a reddit comment; should be able to do something like this:

"Can you put perhaps a thin black stroke around the circles that are controlled by say under 5 addresses and perhaps a thick one around 1 address? Also a small written text of the price really close would be great - hoovering the mouse and it going in less than 2 seconds is hard to keep track of when they’re moving. Thanks excellent tool."

[pmaji]

Completed; now the coloring differentiates between price-points with 5 or more distinct orders behind it.

[theimo1221]

Possible future improvement in #27