7-seg Display - Add a toggle to display A-F instead of using overflow

[Hexicube]

It would be impractical to try and display binary numbers in base 10 using the overflow to the point where you would probably do it before it even hits the display. Currently the overflow is only useful for the specific case of showing 11-15 from a single 4-bit input across two displays.

Perhaps if larger numbers should be displayable in base 10 there should be a separate binary to 7-seg multi-digit converter building, that takes in two 4-bit binary values (0-255) and outputs three 4-bit binary values in the 0-9 range. I highly doubt people will want to go beyond 8-bit numbers.

A-F can be displayed via 7-seg with A b C/c d E F capitalisation.