The previous behavior was to generate hierarchical names for all
labels when copying contents of subcells. This is "safe" for
copying selections without accidentally shorting things through
labeling, but it can make a mess of the selection. Options are
now "select do labels" for the existing behavior, "select no labels"
to not show any labels, and "select simple labels" to show only the
root name of labels in subcells.
not copy labels; not copying labels speeds up the antenna checks
(which don't need labels) greatly. Also fixed several numerical
overflow problems in the antenna checks, which resulted in false
positive errors, as well as nonsensical results.