see #9414 - MapCSS-based tagchecker: provide `{i.key}`, `{i.value}`, `{i.tag}` variables to messages/fixes which refer to the corresponding match condition

git-svn-id: http://josm.openstreetmap.de/svn/trunk@6538 0c6e7542-c601-0410-84e7-c038aed88b3b