Insert V4L2 instrumentation module on session start

Requires V4L2 instrumentation patch for lttng-modules.

Signed-off-by: Wade Farnsworth <wade_farnsworth@mentor.com>
Signed-off-by: David Goulet <dgoulet@efficios.com>
Add MIT license header to session.xsd

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Signed-off-by: David Goulet <dgoulet@efficios.com>