Scripts to support Atmel SAM3 chips

[embitz]

Here are some scripts for the ATSAM3xx line of Atmel/Microchip chips.  Boy were these easier than the NXP LPC scripts.  I don't know why NXP made their chip flashing procedure so difficult.

I also made a small change to the Cortex-M0 section in the atmel-auto.script so that it wouldn't incorrectly detect non-Atmel chips as Atmel when using the auto.script.

Thank you very much indeed