more attempt to support older boost::filesystem...
more attempt to support older boost::filesystem...

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