time-consuming (note the commit message "There are still likely much
better ways to do this"). Worked out a method of hashing the location
of terminals on other planes so that they can be looked up from the
address of the tile. This requires only one pass through the devices
to locate and record the terminals, and no loops through devices when
processing tiles. Also corrected the positioning of the substrate
terminal to be the center position of the device tile, not the substrate
tile. This not only better represents the substrate connections, but
it also eliminates the condition in which many thousands of resistors
converge on the same point, which causes stack overflow. With the
current scheme, stack overflow is unlikely to occur.
14afb4bd52