improving PCLBlock filter for #248
improving PCLBlock filter for #248

mtCarto/PDAL,DougFirErickson/PDAL,jwomeara/PDAL,lucadelu/PDAL,mtCarto/PDAL,jwomeara/PDAL,lucadelu/PDAL,Sciumo/PDAL,lucadelu/PDAL,radiantbluetechnologies/PDAL,DougFirErickson/PDAL,mtCarto/PDAL,radiantbluetechnologies/PDAL,mtCarto/PDAL,jwomeara/PDAL,mpgerlek/PDAL-old,mpgerlek/PDAL-old,Sciumo/PDAL,radiantbluetechnologies/PDAL,Sciumo/PDAL,mpgerlek/PDAL-old,DougFirErickson/PDAL,boundlessgeo/PDAL,DougFirErickson/PDAL,jwomeara/PDAL,boundlessgeo/PDAL,mpgerlek/PDAL-old,boundlessgeo/PDAL,lucadelu/PDAL,Sciumo/PDAL,boundlessgeo/PDAL,radiantbluetechnologies/PDAL