Makefile: update to make sources only releases
gc scripts/update_apt: not needed anymore in the sources repo
gc scripts/collect.sh that is not used anymore
Makefile: update comment
runner_core.py: treat mlab-ns like rendezvous

When mlab-ns or rendezvous terminate, we don't need to detach
the streaming logger, because the test is indeed beginning.

Fixes the problem with the dash test that stops after four
seconds when run on the command line, which was reported
by Antonio a couple of days ago.
mod_dash: print the server address at INFO level

Simplifies first-cut debugging without forcing one to re-run
the test with -v.

Difficulty spotted and reported by Antonio Servetti.
Neubot/0.4.16.9 released