GNU binutils for Atmel AVR cross-development

Prerequisite for the GCC for AVR cross-compilation environment.

Also included now is the "AVR COFF beta" patch.  It allows avr-objcopy to
generate AVR (extended) COFF files to be used on Atmel AVR Studio and
VMLAB.  Note that this patch has known issues, see
http://www.sax.de/~joerg/README.coff-avr-patch

In addition to the stock binutils-2.16 distribution, support for the
following AVR devices has been added by a private patch:

  ATtiny25/45/85
  AT90PWM2/3
  ATmega164/324/644
  ATmega329/3290/649/6490
  ATmega640/1280/1281
