This changeset does two things: introduces a new RemoteDisconnected exception
(that subclasses ConnectionResetError and BadStatusLine) so that a remote
server disconnection can be detected by client code (and provides a better
error message for debugging purposes), and ensures that the client socket is
closed if a ConnectionError happens, so that the automatic re-connection code
can work if the application handles the error and continues on.

Tests are added that confirm that a connection is re-used or not re-used
as appropriate to the various combinations of protocol version and headers.

Patch by Martin Panter, reviewed by Demian Brecht.  (Tweaked only slightly by
me.)

array_array_frombytes() is used in other functions, but it's signature was
changed. Closes issue #23866.

returns bool.  tkinter.BooleanVar now validates input values (accepted bool,
int, str, and Tcl_Obj).  tkinter.BooleanVar.get() now always returns bool.

returns bool.  tkinter.BooleanVar now validates input values (accepted bool,
int, str, and Tcl_Obj).  tkinter.BooleanVar.get() now always returns bool.

Patch by Makoto Kato.

Patch by Makoto Kato.

PyArg_Parse instead of PyArg_ParseTuple if possible.

(empty) definition of the methoddef macro: it's only generated once, even
if Argument Clinic processes the same symbol multiple times, and it's emitted
at the end of all processing rather than immediately after the first use.

the wait is cancelled, the future *fut* is now also cancelled.

in Parser/pgen.c.