Internal flashing (get rid of avrdude)

[smurfy]

Related to: ArduPilot/apm_planner#62

[smurfy]

Well i added my own flashing code in a separate branch because it needs a lot of testing.
I only tested with an arduino mega.

I managed to semi brick it during development (had to clear flash/reflash bootloader using an external programmer)

But now i managed to flash different hex files and all verified ok. it also worked to connect using the missionplanner terminal. (but hangs after the greeting, i guess due to missing sensors/hardware on the arduino mega)