Patch by Wojtek Ruszczewski.

Following suggestions from Clément.

HTTPStatus.NOT_FOUND).  Patch by Demian Brecht.

Patch by Martin Panter.

instead of reading /dev/urandom, to get pseudo-random bytes.

future

* Fix a race condition in BaseSubprocessTransport._try_finish().

  If the process exited before the _post_init() method was called, scheduling
  the call to _call_connection_lost() with call_soon() is wrong:
  connection_made() must be called before connection_lost().

  Reuse the BaseSubprocessTransport._call() method to schedule the call to
  _call_connection_lost() to ensure that connection_made() and
  connection_lost() are called in the correct order.

* Add repr(PipeHandle)

* Fix typo

has no event loop even if assertions are disabled.

This is to keep buildbots running while we figure out the best long-term fix.