Support package for Piaware sdcard images
This builds a Debian package that manages the stuff specific to a Piaware sdcard image:
- apt configuration for the FlightAware repository
- Boot splashscreen
- First-boot generation of ssh host keys
- Applying network and receiver configuration from piaware-config.txt settings
- Text-mode status display on the first virtual console
- initramfs support
- Management of /boot/config.txt when kernels or initramfs are updated
- Warns about default passwords when ssh is enabled