- rename UE_NO_LOG to DISABLE_LOG_X
  because the name is misleading. The full software
  is impacted, not only the UE part
- same for compilation option ---ue-no-log
  that becomes --disable-log
- keep LOG_X for the standard case, that is the
  case without DISABLE_LOG_X where printf has been
  put. Two reasons:
  * printf is not realtime friendly
  * keep behavior similar for other users who may
    be troubled by different logs that don't add
    any benefit to previous logs