Native GCC that runs on target.

To save disk space, this GCC uses dynamic linking on the target box. There
are configuration options to include libstdc++.a, libc.a and libpthread.a
if staticly linked binaries are needed.

For now, this was only tested on arm (EABI) and mips targets. Others to be
done...

   Christian Beier <cb@shoutrlabs.com>
