fix default mmap size

Signed-off-by: Julien Desfossez <jdesfossez@efficios.com>
Handle inactive streams when creating the iterator

If a live session was already started before the viewer connects and is
now idle, it will be sending beacons (packet_size = 0), in the viewing
plugin, we need to know that as soon as the iterator is created (before
a get_next).

Signed-off-by: Julien Desfossez <jdesfossez@efficios.com>
[MERGE] viewer fix handle inactive trace at iter create

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