converted to the new PropertyRecord type. Since this was in the
CIFPropRecordPath() subroutine, which has always been problematic
and generally useless, I took the opportunity to make that function
dependent on an option set by "gds savepaths true", with the option
set to "false" by default, so "path" properties will no longer be
created from GDS input unless the option is manually set to "true".
Also: Found that the returned boolean from "box exists" is
sometimes getting overwritten with a NULL result, causing a spurious
Tcl error messages to pop up. I could not find where this
overwriting happens (probably in a tag callback), so I just took the
hack approach of converting a NULL result to "false", which is always
safe to do.