Multiple GPS support was added for the special use case where a UMPC with a built in GPS is used with StreetDeck and docked in a car that has a second USB GPS receiver
attached to the docking station for use while in a vehicle.
When configured for multiple GPS use: If the primary GPS is present or becomes present after a USB device insertion notification, it will automatically be selected as the GPS signal StreetDeck uses. If the primary GPS device is not present, it will use the secondary GPS device for the GPS signal StreetDeck uses. If neither the primary GPS, nor the secondary GPS is present, StreetDeck, will look for network broadcast packets. All GPS selection settings made in settings will be overridden by the GPSDevice.txt file.