Big refactoring of relation context menu actions, removing duplicate and similar code. Any behavior change is a bug!
see #7846: Harmonize Relation popup menus and actions,
Please check relation-actions in Selection List, Relation List and Properties dialogs.


git-svn-id: http://josm.openstreetmap.de/svn/trunk@5793 0c6e7542-c601-0410-84e7-c038aed88b3b