Release of libvirt-0.9.13
    
    - S390: support for s390(x)
    - snapshot: implement new APIs for esx and vbox
    - snapshot: new query APIs and many improvements
    - virsh: Allow users to reedit rejected XML
    - nwfilter: add DHCP snooping
    - Enable driver modules in libvirt RPM
    - Default to enable driver modules for libvirtd
    - storage backend: Add RBD (RADOS Block Device) support
    - sVirt support for LXC domains inprovement
    - a lot of bug fixes, improvements and portability work