fix #8951 - fix clearing of primitive metadata

git-svn-id: http://josm.openstreetmap.de/svn/trunk@6140 0c6e7542-c601-0410-84e7-c038aed88b3b
fix #8911 - Allow `toll=yes` + `route=ferry` (patch by dommage)

git-svn-id: http://josm.openstreetmap.de/svn/trunk@6141 0c6e7542-c601-0410-84e7-c038aed88b3b
see #8902 - fix compilation warnings

git-svn-id: http://josm.openstreetmap.de/svn/trunk@6142 0c6e7542-c601-0410-84e7-c038aed88b3b