Call "on_message_aborted" if the user doesn't confirm the
 sending of a mail.

  This allows a mail to be saved to ~/Maildir/drafts, or similar.

  This updates #86.
  Call "on_send_message" hook, after the user presses "y", but
 before sending the message.

  This updates #87
  Call the "on_edit_message" hook, after the editor has terminated.
  Call "on_send_message" from "send_email".

  This updates #87.
  Updated comment for the hook-function.
  Allow index_limit to match against message-headers.

  This updates #89.

  New documentation: http://lumail.org/lua/index_limit.html
Fix setlocale string alloc
Merge branch 'master' of https://github.com/skx/lumail
Fix clang warnings
Fix use of free() instead of delete()
  Update to the wide version of ncurrses.

  This closes #91.
  Updated to allow header-limits to operate on
 multiple headers.

  This closes #89.
  Updated spelling.

  Run "M-x ispell-comments-and-strings" against the code, fixing
 the most obvious errors.
  Fix usage of free() instead of delete().
  Sort basic primitives.
  Added help() primitive.
  New sort type: "header".

  The header-sort sorts by the Date: header present in messages.
 It is slow.

  This closes #85.