At present the low-can binding (agl-service-can-low-level) fails to start if the interfaces specified in its /etc/dev-mapping.conf configuration file are not present.  When booting on platforms without physical CAN hardware, this leads to signal composer having issues as well since it has low-can as a dependency, and complicates testing of both bindings.  To ease this, it is proposed that a mechanism be added to bring up the interface(s) in /etc/dev-mapping.conf as virtual CAN device/devices if there is no hardware CAN device present.