Feature 45/multiple screens + touch screen control for smaller side screen

[whitfijs-jw]

• Big restructure to handle second screen without large amounts of duplicated QML
• Qt app now supports an optional 800x480 secondary touch screen on HDMI2
• Added new assets for 240, 740/940/850, r-sport, etc style accessory gauges
• Gauges displayed on secondary screen change with the primary screen gauge style
• added support for USB multitouch with a modified the rootfs and linux kernel to support touch on the secondary screen