message: reactor.network.UTPServer: More precise log categories.
diff: #include <elle/Buffer.hh>
  #include <elle/log.hh>
  +#include <elle/os/environ.hh>
  #include <reactor/network/utp-server-impl.hh>
  #include <reactor/network/utp-server.hh>
  @@ -108,8 +109,8 @@ namespace reactor
  uint64
  on_error(utp_callback_arguments* args)
  {
  - ELLE_DEBUG("on_error %s", utp_error_code_names[args->error_code]);
  auto s = get(args);
  + ELLE_DEBUG("on_error %s on %s", utp_error_code_names[args->error_code], s);
  if (s)
  s->on_close();
  return 0;
  @@ -166,7 +167,8 @@ namespace reactor
  uint64
  on_log(utp_callback_arguments* args)
  {
  - ELLE_DEBUG("utp: %s", args->buf);
  + ELLE_LOG_COMPONENT("reactor.network.UTPServer.backend");
  + ELLE_DEBUG("utp: %s", (const char*)args->buf);
  return 0;
  }
  @@ -294,6 +296,8 @@ namespace reactor
  utp_context_set_option(this->_ctx, UTP_INITIAL_TIMEOUT, 300);
  utp_context_set_option(this->_ctx, UTP_TIMEOUT_INCRASE_PERCENT, 150);
  utp_context_set_option(this->_ctx, UTP_MAXIMUM_TIMEOUT, 5000);
  + if (elle::os::inenv("ELLE_UTP_DEBUG"))
  + utp_context_set_option(this->_ctx, UTP_LOG_DEBUG, 1);
  }
  UTPServer::Impl::~Impl()
  @@ -320,6 +324,7 @@ namespace reactor
  void
  UTPServer::Impl::_check_icmp()
  {
  + ELLE_LOG_COMPONENT("reactor.network.UTPServer.ICMP");
  #if defined(INFINIT_MACOSX)
  if (this->_icmp_fd == -1)
  {
  