from ext2spice due to "equiv" statements in the .ext file. The
algorithm was not properly keeping the port as the preferred
name of the node, resulting in the non-preferred name being
used instead of the port name in the output. This would happen
only if there was a label on a net that had a different name than
the port name. The error became much more prevalent after changing
the extract behavior to make "extract do aliases" default. Also
fixed a somewhat related minor error in which magic would print an
error message about ports being shorted together on the same kind
of net where both a port and a (different) label were attached to
the net. Since the non-port label is not a preferred name, then
there should be no warning message. The warning is only intended
for cases where two (or more) ports are truly shorted together.