[mkgmap-dev] Commit r4099: document special tag mkgmap:stylefilter and add a check that it is not modified in the relations style file.

Version mkgmap-r4099 was committed by gerd on Thu, 01 Feb 2018 document special tag mkgmap:stylefilter and add a check that it is not modified in the relations style file. http://www.mkgmap.org.uk/websvn/revision.php?repname=mkgmap&rev=4099