remove forward stuff from defs.h
remove defs.h from local.c and forward.c

The local tracer now waits for the remote tracer to connect,
that's no more the other way around.

All the remote tracers (textlog, enb, vcd) have also been converted.

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

plus there is a default now