Menus.cpp no longer link dependent on top level menu definitions...

... They all use the registry.

(This link dependency was not shown in diagrams generated by scripts/graph.pl,
because it was not reflected in Menus.h but was done using extern declarations
within Menus.cpp.  That was a cheat, but it let all the other dependencies
be exposed in the graph and mitigated first.)

src/menus/HelpMenus.cpp

@@ -523,10 +523,10 @@ static CommandHandlerObject &findCommandHandler(AudacityProject &) {
 
 #define FN(X) (& HelpActions::Handler :: X)
 
-// Under /MenuBar
-MenuTable::BaseItemSharedPtr HelpMenu()
+namespace {
+using namespace MenuTable;
+BaseItemSharedPtr HelpMenu()
 {
-   using namespace MenuTable;
    static BaseItemSharedPtr menu{
    ( FinderScope{ findCommandHandler },
    Menu( wxT("Help"), XO("&Help"),
@@ -602,4 +602,11 @@ MenuTable::BaseItemSharedPtr HelpMenu()
    return menu;
 }
 
+AttachedItem sAttachment1{
+   wxT(""),
+   Shared( HelpMenu() )
+};
+
+}
+
 #undef FN