#5713: Handle 421 error codes during sendmail by closing the socket.

This is a partial fix to the issue of servers disconnecting unexpectedly; in
this case the 421 says they are disconnecting, so we close the socket and
return the 421 in the appropriate error context.

Original patch by Mark Sapiro, updated by Kushal Das, with additional
tests by me.
Merge: #5713: Handle 421 error codes during sendmail by closing the socket.

This is a partial fix to the issue of servers disconnecting unexpectedly; in
this case the 421 says they are disconnecting, so we close the socket and
return the 421 in the appropriate error context.

Original patch by Mark Sapiro, updated by Kushal Das, with additional
tests by me.
Merge: #5713: Handle 421 error codes during sendmail by closing the socket.

This is a partial fix to the issue of servers disconnecting unexpectedly; in
this case the 421 says they are disconnecting, so we close the socket and
return the 421 in the appropriate error context.

Original patch by Mark Sapiro, updated by Kushal Das, with additional
tests by me.
remove the long obsolete mention of universal newlines mode only being
available when configured at compile time.
merge
merge
Refactor the Windows specific and POSIX specific implementations of
listdir into two separate coherent functions rather than interleaved
#ifdef's.
#5713: fix timing issue in smtplib tests.
Merge: #5713: fix timing issue in smtplib tests.
Merge: #5713: fix timing issue in smtplib tests.
#5712: Preemptively fix some other possible timing issues.
Merge: #5712: Preemptively fix some other possible timing issues.
Merge: #5712: Preemptively fix some other possible timing issues.
Fix import
Refactor the common code out of the posix and windows listdir
implementations from my previous commit into the higher level
function.
merge heads
#5713: One more test_smtplib timing fix.
Merge: #5713: One more test_smtplib timing fix.
Issue #17209: curses.window.get_wch() now handles correctly KeyboardInterrupt (CTRL+c)
(Merge 3.3) Issue #17209: curses.window.get_wch() now handles correctly KeyboardInterrupt (CTRL+c)