b43-fwcutter added

Hi,
Here a new package called b43-fwcutter useful for Broadcom firmwares.
As you can see, I didn't use <code>make PREFIX=/usr install</code> because the <code>Makefile</code> attempts to modify the permissions of the folder <code>$PREFIX/bin</code>.
It's unacceptable, so I used <code>vinstall</code> instead.