This patch cleans up the Packet class attributes used to
keep track of how many times packets have been sent and
the last time they were sent. This is used by the PacketTracker
and the tx threads for transmitting packets
The messaging.py now is nothing but a shell that
contains a link to packets.NULL_MESSAGE to help maintain
some backwards compatibility with plugins.
Packets dataclass has fully replaced messaging objects.
This patch adds the needed code to construct the raw output
string for sending a GPSPacket.
TODO: Need to incorporate speed, course, rng, position ambiguity ?
TODO: Need to add option to 'compress' the output location data.
This patch reworks all the packet processing to use the new
Packets objects. Nuked all of the messaging classes.
backwards incompatible changes
all messaging.py classes are now gone and replaced by
packets.py classes