Convert most demos to GLES 2

Also fix Viewport error in 3D scaling demo, add an icon to Multiplayer Bomber, and rename BPM sync files.

networking/websocket_minimal/client.gd

@@ -46,7 +46,7 @@ func _on_data():
 	print("Got data from server: ", _client.get_peer(1).get_packet().get_string_from_utf8())
 
 
-func _process(delta):
+func _process(_delta):
 	# Call this in _process or _physics_process. Data transfer, and signals
 	# emission will only happen when calling this function.
 	_client.poll()

networking/websocket_minimal/project.godot

@@ -17,3 +17,7 @@ _global_script_class_icons={
 
 config/name="WebSocket Minimal Demo"
 run/main_scene="res://Main.tscn"
+
+[rendering]
+
+quality/driver/driver_name="GLES2"

networking/websocket_minimal/server.gd

@@ -50,7 +50,7 @@ func _on_data(id):
 	_server.get_peer(id).put_packet(pkt)
 
 
-func _process(delta):
+func _process(_delta):
 	# Call this in _process or _physics_process.
 	# Data transfer, and signals emission will only happen when calling this function.
 	_server.poll()