offset button redesign


git-svn-id: http://svn.openstreetmap.org/applications/editors/josm/plugins@29386 b9d5c4c9-76e1-0310-9c85-f3177eceb1e4
translation fix


git-svn-id: http://svn.openstreetmap.org/applications/editors/josm/plugins@29387 b9d5c4c9-76e1-0310-9c85-f3177eceb1e4