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

diff --cc git-send-email.perl
Simple merge