Save state feature for VirtualBox and VMware. New "On close" setting to

select the action to execute when closing/stopping a Qemu/VirtualBox/VMware VM.

gns3server/controller/__init__.py

@@ -123,7 +123,7 @@ class Controller:
         for vm in vms:
             # remove deprecated properties
             for prop in vm.copy():
-                if prop in ["enable_remote_console", "use_ubridge"]:
+                if prop in ["enable_remote_console", "use_ubridge", "acpi_shutdown"]:
                     del vm[prop]
 
             # remove deprecated default_symbol and hover_symbol