deploy: Install qemu-kvm from wheezy-backports

ci/schemas/one_node_wheezy/packages.conf

@@ -4,5 +4,6 @@ python-scapy = 2.2.0+rfc6355-1
 snf-ganeti = unstable
 ganeti2 = unstable
 python-django-eztables = 0.3.3-1~snf~0.2
+qemu-kvm = wheezy-backports
 
 [ubuntu]

snf-deploy/conf/packages.conf

@@ -4,5 +4,6 @@ python-scapy = 2.2.0+rfc6355-1
 snf-ganeti = unstable
 ganeti2 = unstable
 python-django-eztables = 0.3.3-1~snf~0.2
+qemu-kvm = wheezy-backports
 
 [ubuntu]

snf-deploy/files/etc/apt/sources.list.d/synnefo.wheezy.list

 deb http://ftp.de.debian.org/debian wheezy main non-free contrib
+deb http://ftp.de.debian.org/debian wheezy-backports main non-free contrib
 
 deb http://apt.dev.grnet.gr wheezy/
 deb http://apt.dev.grnet.gr unstable/

snf-deploy/snfdeploy/base.py

@@ -201,7 +201,7 @@ apt-mark hold {1}
         info = config.get_package(package, self.node.os)
         if info in \
                 ["squeeze-backports", "squeeze", "stable",
-                 "testing", "unstable", "wheezy"]:
+                 "testing", "unstable", "wheezy", "wheezy-backports"]:
             apt_get += " -t %s %s " % (info, package)
         elif info:
             apt_get += " %s=%s " % (package, info)