[mkgmap-dev] Commit r4120: merge again from branch dem-tdb, now with last changes to that branch

Version mkgmap-r4120 was committed by gerd on Thu, 15 Feb 2018 merge again from branch dem-tdb, now with last changes to that branch http://www.mkgmap.org.uk/websvn/revision.php?repname=mkgmap&rev=4120