first step: let the tracee connect before the remote tracer
and let's have a "no wait" mode where the local tracer starts
the tracee before the remote tracer is connected

get rid of T_send(), no use anymore

The T only works when it's TRUE, the version without shared memory
is not supported anymore.

can be deactivated on the command line or in the gui

- adding T macros here and there
- modify the T_messages.txt
- modify enb.c to trace them in the RRC view

plus add rrc connection setup complete tracing

as special events.

If we store all received events to a file, this dump is now
self-contained. Helps to analyze traces.

Some functions have also been factorized in the process, too much
duplication.

(Also tracer/Makefile was forgotten in previous commit, included
in this one...)

many assumptions about X backed were made, to be refined if does not
work properly in some setups

it seems more natural to stop autoscroll with button 3 and start it
with button 1