new opencpn and pypilot plugin

[rastam4n]

there are a few changes to git, and also the nmea processing is still broken and I haven't managed to push the fix yet..  I did fix it though.

Looks like you have been busy updating git, based on the dates of changes? Have you pushed the nmea processing fix yet?

I would love the test the new versions, but I need to be able to revert to a  working backup if things don't work correctly while I am out on the water.
I don't use an SD card I wonder what an easy solution for this would be without having to swap SSD cards out... I was thinking maybe a dual boot setup... is that possible on rpi?