basic handling of live_timer, for now just a printf

Signed-off-by: Julien Desfossez <jdesfossez@efficios.com>
Create relayd session from the sessiond

Move the relayd session creation from the consumer to the relayd. No
change in behaviour expected here, just prepare for the next patch to
allow the sessiond to pass additionnal parameters in the relayd session
creation required for live tracing (hostname, session name, flags, etc).

Signed-off-by: Julien Desfossez <jdesfossez@efficios.com>