vdsm-tool: roll out self signed certificates in vdsm-tool.

This is handled in a new 'ModuleConfigure' named 'certificates'.
Libvirt module now requires 'certificates'.

certificates are not remove during removeConf.

previously certificates where generated on init.

Change-Id: I53d927e49920e8c45d02718f2b6ef5dff63eead0
Bug-Url: https://bugzilla.redhat.com/show_bug.cgi?id=1127877
Signed-off-by: Mooli Tayer <mtayer@redhat.com>
Reviewed-on: http://gerrit.ovirt.org/31562
Reviewed-by: Dan Kenigsberg <danken@redhat.com>