Checkpoint-restore tool v0.7

Hi, all!

The checkpoint-restore tool v0.7 release is ready and out,
the changelog is at http://criu.org/Download/criu/0.7
the sources are at http://download.openvz.org/criu/criu-0.7.tar.bz2

The main news about the release is that the ptrace extension to get/set sigmask on processes and the memory changes tracker (a.k.a. soft-dirty thing) are merged into Linux-3.11. With this done, we finally have everything, that is really critical for C/R, and thus the project is no longer *that* kernel-dependent.

That said, from now on we shall concentrate on improving the tool performance and stability, rather than adorning the kernel :) Also, we no longer have to keep the CRIU releases in sync with the kernel releases, so the next one we be done as soon as it's ready, not when the Linux-3.12 is out.

Thanks everyone who helped with the v0.7, especially with the soft-dirty stuff!

Have fun!