Tools: add can_sitl_nodev.sh which doesn't require a (e.g.) babel to run

Tools/scripts/CAN/can_sitl_nodev.sh

@@ -0,0 +1,22 @@
+#!/bin/bash
+
+# once run, you can configure SITL for CAN just like a real board, with the CAN parameters
+#
+# CAN_P1_DRIVER=1
+# CAN_D1_PROTOCOL=1
+
+# once running you can also attach uavcan_gui_tool to vcan0 to monitor the CAN bus
+
+set -e
+set -x
+
+# cleanup from a previous run
+sudo killall -9 slcand 2> /dev/null || true
+for m in slcan can-gw vcan can_raw can; do
+    sudo rmmod $m 2> /dev/null || true
+done
+
+sudo modprobe vcan
+sudo ip link add dev vcan0 type vcan
+sudo ip link set up vcan0
+sudo modprobe can-gw