New feature:
===========
The RELAYCLIENT environment variable can be set to "@domain.name" to
cause zdkimfilter to use that as the signing domain name.  Note that
the variable will be reset in case the remote client authenticates,
thereby turning to normal signing behavior.


New configuration parameter:
===========================
let_relayclient_alone (bool)
Disables the new feature, as it conflicts with a seldom used Courier
feature (similar to percent relay).


Database changes:
================
Tweak the db_sql_check_user query into using per-user limits.  The query
is in odbx_example.conf,  It compares the sum of recipients (rcpt_count)
in the last 24 hours against a fixed value of 10000, which you might
have lowered.

First, add a per user field to compare against. for example:

ALTER TABLE user \
  ADD COLUMN rcpt_max_perday MEDIUMINT UNSIGNED NOT NULL DEFAULT 10000;

Next, alter the query in your zdkimfilter.conf so as to compare to
another subquery instead of the fixed value.  The subquery is:

(SELECT rcpt_max_perday FROM user WHERE id = $(user_ref))

If you set RELAYCLIENT=@domain.name in some smtpaccess file, recipients
will be counted against postmaster@domain.name.  So that user may need
a higher limit than the default.


Bug fixes and other changes:
===========================
An empty line in message header used to be treated badly.

Nettle version 3 support.

Added debian directory