[mkgmap-dev] Commit r4565: implement undocumented option --x-keep-empty-value-tags to disable the removal of empty tags while parsing OSM input

Version mkgmap-r4565 was committed by gerd on Wed, 22 Jul 2020 implement undocumented option --x-keep-empty-value-tags to disable the removal of empty tags while parsing OSM input http://www.mkgmap.org.uk/websvn/revision.php?repname=mkgmap&rev=4565