Suppress bit x which was set on management_addr.h file
Simplify communication module comm.c (so that porting to Windows is more simple)

- Do not use signals any more to stop a connect(). Rely on select() with a timeout.
- Do not use signals any more to stop an accept(). Use shutdown()
- Adapt testComm.c unit test to this thew design.
- With all of these changes, we do not need module signalMgt any more.
- Moreover, #define ERROR which was made in errorTrains.h is no longer needed. We suppress it (this is a good news, because this definition was causing problems for windows porting).