HTML and Unicode MOTD

BugfixedHL client and server supports three types of MOTD. On the server, all of them are optional.

• Text MOTD
  File: motdfile (default: motd.txt).
  Encoding: Windows−1252.
  Remarks: Some clients may replace the fonts or interpret it as UTF-8.
  Don't rely on anything but ASCII (English language).

• Unicode MOTD
  File: motdfile_unicode (default: motd_unicode.txt).
  Encoding: UTF-8.
  Remarks: BugfixedHL doesn't support characters outside the Unicode Basic Multilingual Plane.

• HTML MOTD
  File: motdfile_html (default: motd.html).
  Encoding: UTF-8.

However, the last two types require some server configuration changes.

1. Enable sv_bhl_query_vars. This will enable querying of aghl_supports client cvar to determine which MOTDs are supported.
2. If the server supports old p47 clients (like NGHL), enable sv_bhl_query_wait_for_id to prevent them from being kicked with svc_bad error.
3. Enable sv_bhl_defer_motd. It will defer sending of MOTD until after query response was received. It may delay showing of the MOTD dialog but usually query response arrives before client is fully loaded so there are no issues with that.