Added a small python programm which is executed if the board is yun

[maximilianvoss]

To deploy new code to yun it has to be reseted to access the bootloader.
Reset is done by opening the serial port with 1200 baud and closing it again.

Done so with a python script which is executed on the command line.
Assuming python is installed on the system in system path + python serial module.

Don't know if there is a nicer way, but without reset, it won't upload

[oldmud0]

Needs to check if Python or stty exist. Also, there's probably a better way to do the set( thing, but that's the most minimal program that can be made for the reset task.