* add a new example using transport and protocol
* rewrite the example using streams to make it much simpler (remove error
  handling, use a simpler Python code)
* copy (and adapt) more documentation from the subprocess module:

  - add a note about Process.wait() deadlock
  - add a note about shell injection
  - etc.

* sort Process methods and attributes in the same order than subprocess.Popen
  methods and attributes, so the documentation looks closer
* list differences between Process and subprocess.Popen APIs

instanciate a subclass of SubprocessProtocol

Modify also the get_pipe_transport() doc to mention explicitly the supported
file descriptors.

Thanks to Ezio for noticing this

The function schedules the execution of coroutines, it's not just a wrapper for
something.

Fix also the reate_unix_connection() doc: the method is not support on Windows,
not need to mention that ssl is not support with ProactorEventLoop.

Patch by Michel Albert.  We don't normally do patches that just tweak
whitespace, but ipaddress is relatively new and the package maintainers
approved the patch.

Patch by Meador Inge.

This gets rid of  Tcl warnings when they are handled later when the root is
already destroyed.

Patch by Chris Jerdonek.

Patch by David Naylor.

Add "closed" or "closing" to repr() of selector and proactor transports

Reported by Jacques Ducasse.

socket