LinuxCNC 2.6.4 New ISO

Due to USB problems on some motherboards a new ISO has been created with 2.6.4.

This issue (non working USB on Baytrail = J1800,J1900,J2900 based) motherboards
has been fixed on the wheezy RTAI kernel as of a few days ago.

Thanks to Brian Morel for chasing down the patch that fixed
the USB issue, Sebastian Kuzminsky for building the distribution kernel
and Chris Radek for packaging it with the latest (2.6.4) ISO image

This is important as these are very nice fanless systems, much faster than the Atom D525s
at the same or lower power