UPnP support

I think I got UPnP working but I can't test it on the RPI
network I think.

Picasso/MainMenu.tscn

@@ -57,6 +57,6 @@ margin_top = 695.152
 margin_right = 1263.36
 margin_bottom = 709.152
 custom_styles/normal = SubResource( 1 )
-text = "Version: 0.0.1"
+text = "Version: 0.2.0"
 [connection signal="pressed" from="VBoxContainer/ConnectButton" to="." method="_on_ConnectButton_pressed"]
 [connection signal="pressed" from="VBoxContainer/HostButton" to="." method="_on_HostButton_pressed"]

Picasso/Networking.gd

@@ -6,7 +6,6 @@ const MAX_PLAYERS = 5
 
 # To be used for UPNP later
 var server_ip = DEFAULT_IP
-var server_port = DEFAULT_PORT
 
 var peer
 
@@ -19,15 +18,26 @@ onready var _multimesh: MultiMeshInstance
 func _ready():
 	get_tree().connect("network_peer_disconnected", self, "_on_player_disconnected")
 	get_tree().connect("network_peer_connected", self, "_on_player_connected")
+	get_tree().connect("server_disconnected", self, "_on_server_disconnect")
 
 func set_multi_mesh(mm: MultiMeshInstance):
 	_multimesh = mm
 
 func create_server(name):
+	# setup UPNP so you don't need to port-forward
+	var upnp = UPNP.new()
+	upnp.discover()
+	upnp.add_port_mapping(DEFAULT_PORT)
+	server_ip = upnp.query_external_address()
+	if server_ip:
+		Debug.set_field("external ip", server_ip)
+	else:
+		Debug.set_field("external ip", "UPnP failed")
+
 	self_data.name = name
 	players[1] = self_data
 	peer = NetworkedMultiplayerENet.new()
-	peer.create_server(server_port, MAX_PLAYERS)
+	peer.create_server(DEFAULT_PORT, MAX_PLAYERS)
 	get_tree().set_network_peer(peer)
 	_load_game()
 
@@ -35,7 +45,7 @@ func connect_to_server(name, ip):
 	self_data.name = name
 	get_tree().connect("connected_to_server", self, "_connected_to_server")
 	peer = NetworkedMultiplayerENet.new()
-	peer.create_client(ip, server_port)
+	peer.create_client(ip, DEFAULT_PORT)
 	get_tree().set_network_peer(peer)
 
 func disconnect_from_server():
@@ -79,6 +89,9 @@ func _on_player_disconnected(id):
 	players.erase(id)
 	get_tree().get_root().get_node(str(id)).queue_free()
 
+func _on_server_disconnect():
+	disconnect_from_server()
+
 remotesync func update_color(id, color: Color):
 	players[id].paint_color = color
 	get_tree().get_root().get_node(str(id)).set_color(color)