Cleanup the examples that we use

- Make it compile with no warning
- Don't compile the other binaries by default
- Sanitize the file naming schema
- Have the test running script build the binaries on need
- Add copyright headers to the source files
adapt the README to recent cleanups
cosmetics
allow the send example to run out of simterpose, eg under strace
allow msg example to run out of simterpose
Write the strace-like outputs to separate files

It allows to diff that output to a real strace output.
Now, we have to get that damn output kinda matching with reality.
Wish me luck (and faith)!
ignore cruft
cosmetics

Use the same naming schema for simterpose-*.log and strace-*.log
(for what's within that *)
that's a fishy smell, even under simterpose standards :(
kill a useless function. I can call MSG myself
HAHA, send all automatic logs to the separate strace-like files

We rewrote every bit we use in SimGrid, but it worth it :)
show the diff between expected strace and produced one
correct retcode
reindent (no real change)
improve the pretty printing of open(2)'s flags
missing dependency
make strace exactly match for failing open()s
more bits of understanding in the clone issue. Thanks chloé
a world about where to find more info on syscalls arguments
display the brk in the strace

I was hoping that since we don't mediate the brk()s, that would
constitute a good resynchronization point for diff in the strace, but
actually, the returned values differ for some reason. I can't
understand why the memory layout would be different in strace and in
simterpose.