Cleanup dependencies

This removes the canusb packages reliance on the nmea2k package. It also
moves the goroutine for reading and assembling FastPackets out of the
top level argo package and into the canusb package.
Bug fixes after testing CANUSB refactor

These fixes should complete the refactor of the CANUSB code, allowing us
to begin refactoring Actisense code.
Refactor actisense driver

Refactor actisense to be more like canusb lib.
Remove main loop from Goroutine
Fixes to actisense after testing
Added abstracted CAN library
Change to n2k ParsePacket function to use new CAN package
Update canusb to use new CAN package
Update Actisense to use new CAN package
Update to use new Actisense and CANUSB packages

With changes reflecting updates to Actisense and CANUSB and the addition
of the new can package.
Oops...
Bugfixes in CANUSB Write method
Automatically Fast Packets in nmea2k.PgnList With CANUSB driver