option "labels ... cellid" to handle some vendor files where
apparently to get around the 30-character cell name limit, the
actual cellname is encoded on a text layer. Added new cifop
"boundary" (no arguments) for cases where a cell abutment box
is encoded on a GDS layer; this now translates the bounding
box to the FIXED_BBOX property, as is done with the LEF bounding
box. Also corrected the property set function to free existing
property value allocated memory when overwriting a property with
a new value.
Tim Edwards