*) rename imap to mail, sort pop3/imap functions
*) smtp auth support
*) pop3 starttls only
*) fix segfault if cram-md5 was used without apop

    *) Feature: the "bind" option of the "listen" directive in IMAP/POP3
       proxy.

    *) Bugfix: if the same capture in the "rewrite" directive was used more
       then once.

    *) Bugfix: the $sent_http_content_type, $sent_http_content_length,
       $sent_http_last_modified, $sent_http_connection,
       $sent_http_keep_alive, and $sent_http_transfer_encoding variables
       were not written to access log.

    *) Bugfix: the $sent_http_cache_control returned value of the single
       "Cache-Control" response header line.

    *) Feature: the ngx_http_dav_module supports the MKCOL method.

    *) Feature: the "create_full_put_path" directive.

    *) Feature: the "$limit_rate" variable.