Menubar: 'Exec: ' item addition to the end.

This adds a 'Exec: <your-cmd-here>' item to the end of the list,
which appears only if there is at least one application entry in
the list. This is useful, when the program is not in the list of menubar
entries (e.g. it does not have a .desktop file).

When there is are no matching application entries, the 'Exec: ' item is
silently removed, as we already have the same in the prompt.

Signed-off-by: Ignas Anikevicius (gns_ank) <anikevicius@gmail.com>
Signed-off-by: Uli Schlachter <psychon@znc.in>

lib/menubar/init.lua.in

@@ -93,9 +93,6 @@ end
 -- @param o The menu item.
 -- @return if the function processed the callback, new awful.prompt command, new awful.prompt prompt text.
 local function perform_action(o)
-    if not o or o.empty then
-        return true
-    end
     if o.key then
         current_category = o.key
         local new_prompt = shownitems[current_item].name .. ": "
@@ -158,13 +155,15 @@ local function menulist_update(query)
     end
 
     if #shownitems > 0 then
+        -- Insert a run item value as the last choice
+        table.insert(shownitems, { name = "Exec: " .. query, cmdline = query, icon = nil })
+
         if current_item > #shownitems then
             current_item = #shownitems
         end
         shownitems[current_item].focused = true
     else
-        table.insert(shownitems, { name = "<no matches>", icon = nil,
-                                   empty = true })
+        table.insert(shownitems, { name = "", cmdline = query, icon = nil })
     end
 
     common.list_update(common_args.w, nil, label,