Add method to generate GPGGA sensor data in MPM devices. This needs to
be constructed from TPV and SKY sensor data, and matches the GPGGA
sensor functionality in gpsd_iface.cpp.
gpsd connection is not reliable.
Adding more error handling to re-connect during polling.
Add control flows to get_gps_time in order to give an effect of getting
the value on pps edge.
- Refactoring GPSd interface to be instead wrapped by a
GPSDIfaceExtension class. This class will faciliate "extending" an
object, allowing that object to call the GPSDIfaceExtension methods as
their own.
- New MPM devices (or whatever else) can now use the GPSDIfaceExtension
class instead of writing their own GPSDIface handling functions.
- N3XX now instantiates a GPSDIfaceExtension object, and extends
itself. This means that an n3xx object can call the `get_gps_time`
method as its own, for example.
- N3XX must get through initialization in order for the GPSd methods
to be registered.
