libguestfs security, bug fix, and enhancement update

1:1.16.19-1 - Rebase to libguestfs 1.16.19 resolves: rhbz719879 - Rebuild against augeas 0.9.0-3.el6 related: rhbz808662 - Fix: Don't abort inspection if mdadm.conf ARRAY doesn't have a uuid. - Switch back to git for patch management. 1:1.16.18-2 - Rebase to libguestfs 1.16.18 resolves: rhbz71987...