[Therion] Add UIS ceiling-step/meander to Therion symbol sets?

Hi The examples of NZSS line ceiling-step and line ceiling-meander that I posted last month are pretty close to the UIS symbols I think. http://therion.speleo.sk/wiki/doku.php?id=metapost#general_symbol_examples (they are just the reflection of the SKBB linetypes) Perhaps they could be added to Therion's UIS symbol set, which is currently blank for these two symbols. Also the UIS chimney symbol should be replaced with the above if this http://www.carto.net/neumann/caving/cave-symbols/ is a reliable reference. Regards Bruce