Add libvirt-driver-lxc to nova-libvirt
Add libvirt-driver-lxc to nova-libvirt

libvirt is compiled with lxc support.  On Ubuntu hosts, without this file
libvirt is nonusable.  The container exits immediately.

Change-Id: Ifbc2d75defe082cbe3b80b1821799f1f965c2a85

stackforge/kolla,bdastur/kolla,mandre/kolla,openstack/kolla,LoHChina/kolla,jakedahn/kolla,nihilifer/kolla,mandre/kolla,GalenMa/kolla,chenzhiwei/kolla,fdumpling/kolla,nihilifer/kolla,negronjl/kolla,LoHChina/kolla,invenfantasy/kolla,toby82/kolla,dardelean/kolla-ansible,dardelean/kolla-ansible,meticulo3366/kolla,HackToday/kolla,intel-onp/kolla,chenzhiwei/kolla,tonyli71/kolla,coolsvap/kolla,invenfantasy/kolla,chenzhiwei/kolla,meticulo3366/kolla,stackforge/kolla,tonyli71/kolla,mrangana/kolla,bdastur/kolla,limamauricio/mykolla,dardelean/kolla-ansible,jakedahn/kolla,brk3/kolla,fdumpling/kolla,rajalokan/kolla,rahulunair/kolla,intel-onp/kolla,openstack/kolla,toby82/kolla,coolsvap/kolla,brk3/kolla,mandre/kolla,limamauricio/mykolla,LoHChina/kolla,HackToday/kolla,negronjl/kolla,coolsvap/kolla,invenfantasy/kolla,negronjl/kolla,fdumpling/kolla,limamauricio/mykolla,jakedahn/kolla,rajalokan/kolla,rajalokan/kolla,HackToday/kolla,toby82/kolla,stackforge/kolla,GalenMa/kolla,mrangana/kolla,rahulunair/kolla