Minor edits for gui tests to run on both RHEL 6 & 7.

Signed-off-by: Vimal Patel <vipatel@redhat.com>
Changing starting spice vdagent to use the root session.

Signed-off-by: Vimal Patel <vipatel@redhat.com>
Minor changes to restarting gdm to work for both RHEL 6 & 7.

Signed-off-by: Vimal Patel <vipatel@redhat.com>
Modified verification steps of gui tests to work for RHEL 6 & 7.

Signed-off-by: Vimal Patel <vipatel@redhat.com>