Live unit test

Use the script ./tests/unit/test_live_setup to prepare the test :
- spawn a sessiond
- spawn a relayd
- create a live session with 2sec timer on localhost
- enable one UST event
- start the session
- start the app
- start the actual unit test program (test_live)

The actual test :
- connect to the relayd on localhost
- list the sessions (should find only one)
- attach to the first session
- receive all the streams
- get all the metadata
- get one index per stream
- get one data packet

Then the session is stopped, destroyed and the daemons killed.

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