Added libvirt-dev[el] as a required system package

Added libvirt-dev as a system package to install with apt-get and
libvirt-devel as a system package to install with rpm.

Early drafts qualified with "testonly" (meaning to install only if
INSTALL_TESTONLY_PACKAGES is true).  This is needed because installing
libvirt-python version 1.2.5 on Ubuntu 14.04 was observed to fail in
the building step if libvirt-dev is missing.  Later drafts removed
that qualification, because Sean Dague said he thinks libvirt-dev[el]
is always required.

Change-Id: Ie6a272f60059a1f363630f307416b32c450a1ebb
Closes-Bug: 1362948

Author: MikeSpreitzer

files/apts/nova

@@ -18,6 +18,7 @@ sudo
 qemu-kvm # NOPRIME
 qemu # dist:wheezy,jessie NOPRIME
 libvirt-bin # NOPRIME
+libvirt-dev # NOPRIME
 pm-utils
 libjs-jquery-tablesorter # Needed for coverage html reports
 vlan

files/rpms/nova

@@ -11,6 +11,7 @@ iputils
 kpartx
 kvm # NOPRIME
 libvirt-bin # NOPRIME
+libvirt-devel # NOPRIME
 libvirt-python # NOPRIME
 libxml2-python
 numpy # needed by websockify for spice console