fix #9234 - For identified users, notifies periodically (every 5 minutes by default) of new OSM messages he/she has received. All of this is configurable in server access preferences.

git-svn-id: http://josm.openstreetmap.de/svn/trunk@6349 0c6e7542-c601-0410-84e7-c038aed88b3b
Merge branch 'master' into mirror