Merge branch 'sa/send-email-smtp-batch-data-limit' into maint

When "git send-email" wanted to talk over Net::SMTP::SSL,
Net::Cmd::datasend() did not like to be fed too many bytes at the
same time and failed to send messages.  Send the payload one line
at a time to work around the problem.

* sa/send-email-smtp-batch-data-limit:
  git-send-email.perl: Fixed sending of many/huge changes/patches

git-send-email.perl

@@ -1365,7 +1365,11 @@ Message-Id: $message_id
 		$smtp->mail( $raw_from ) or die $smtp->message;
 		$smtp->to( @recipients ) or die $smtp->message;
 		$smtp->data or die $smtp->message;
-		$smtp->datasend("$header\n$message") or die $smtp->message;
+		$smtp->datasend("$header\n") or die $smtp->message;
+		my @lines = split /^/, $message;
+		foreach my $line (@lines) {
+			$smtp->datasend("$line") or die $smtp->message;
+		}
 		$smtp->dataend() or die $smtp->message;
 		$smtp->code =~ /250|200/ or die "Failed to send $subject\n".$smtp->message;
 	}