fix #9468 - validator: allow `highway=motorway_junction` on nodes

git-svn-id: http://josm.openstreetmap.de/svn/trunk@6516 0c6e7542-c601-0410-84e7-c038aed88b3b
fix #9387 - remote control: add ability to add changeset tags

This extends the `load_and_zoom` handler by optional arguments `changeset_comment` and `changeset_source`.

git-svn-id: http://josm.openstreetmap.de/svn/trunk@6517 0c6e7542-c601-0410-84e7-c038aed88b3b