libvirt builds should include packager information

The libvirt configure script has a special feature especially for distro vendors to use when building binary packages which lets them encode a bit of information about the builds, which then ends up in log files. This does not appear to be used in Ubuntu builds which makes it impossible to determine exactly which particular build of libvirt was used by the bug reporter

For example, on Ubuntu currently if you turn on libvirt logging you'll see a message like this:

  2014-06-27 15:12:33.274+0000: 20830: info : libvirt version: 1.2.2

By comparison on Fedora / RHEL systems you'd see something like this:

  2014-06-27 16:30:33.837+0000: 2454: info : libvirt version: 1.2.2, package: 1.fc20 (Unknown, 2014-06-27-15:41:14, mustard.redhat.com)

In particular notice that it includes the precise RPM release number, so that you can figure out exactly which binary package the bug reporter used. eg on Ubuntu this would be the "0ubuntu13" part of the version number in trusty libvirt builds.

Debian/ubuntu packages could set this doing something like this

  when=`date +"%%F-%%T"`
  where=`hostname`
  who="Unknown" (or name of the person or entity doing the build)
  what="0ubuntu13" (or whatever current build is)

  ./configure --with-packager="$who $when $where" \
                         --with-packager-version="$what" \
                        ...other args to configure...

And then check that this has then propagated to the log messages