syslogd: fixed hostname processing and optimizing timestamp parsing for RFC 5424

[dmitry.wagin_ya.ru]

Summary

In RFC 3164 (bsd-format): The Domain Name MUST NOT be included in the HOSTNAME field.
In RFC 5424 (ietf-format): The HOSTNAME field SHOULD contain the hostname and the domain name of the originator in FQDN format.

Without these changes syslogd(8) uses trimdomain() for addresses received from socket by socklist_recv_sock() (via cvthname()) and addresses used by config filtering by readconfigfile() (via cfline()).

Also, RFC 5424 timestamp parsing has been optimized.

Test Plan

Hostname filtering works incorrectly with "-O syslog" in next cases:

• using "+@" filtering - "localhost" (without domain name) is used for comparing with FQDN-names (ex. "localhost.localdomain");
• using "+server.localdomain" filtering, "-H" flag and localdomain clients - "server" (without domain name) is used for comparing with FQDN-names (ex. "bsd.localdomain").

[markj]

Looks reasonable to me, thanks. Please be sure to upload with context, this change is hard to read without it. i.e., generate the raw diff with -U99999.