Setting radio channel for cc2520 as well
Adding shell modules to make certain apps compile

Using printf with msp430 platforms requires adding in the PrintC and
SerialStartC modules, however, on linux these won't compile correctly,
printf obviously does not need a serial connection. By adding these
dummy modules the app will compile unchanged.

Note: to acutally make
    make rpi blip
work with this app, you may need to switch two lines in the Makerules
file. The lines are near the bottom and the switch makes TARGET files
get compiled in before EXTRA make files.