[Rigo] add --upgrade cmdline switch

rigo/rigo_app.py

@@ -885,6 +885,9 @@ class Rigo(Gtk.Application):
         parser.add_argument(
             "--remove",
             metavar="<dep string>", help="remove given dependency")
+        parser.add_argument(
+            "--upgrade", help="upgrade the system",
+            action="store_true", default=False)
         parser.add_argument(
             "--dumper", help="enable the main thread dumper (debug)",
             action="store_true", default=False)
@@ -972,6 +975,13 @@ class Rigo(Gtk.Application):
             task.start()
             managing = True
 
+        if self._nsargs.upgrade:
+            task = ParallelTask(self._avc.upgrade)
+            task.name = "SystemUpgrade"
+            task.daemon = True
+            task.start()
+            managing = True
+
         return managing
 
     def run(self):