wh_messages now holds every message with a channel (all, team, pm, staff,
to_staff, css_say/asay/psay/csay/hsay/cssay) and NULL sender columns for
the console. Seen by a catch-all listener added in Load, which CSS runs
before CS2-SimpleAdmin's (added in OnAllPluginsLoaded), so gagged lines and
@ chat are kept before SimpleAdmin stops or rewrites them. Replaces
001_CreateTables in place: drop wh_messages and wh_migrations first.
/pm (/w) with names, #userid, SteamIDs, @me, @aim, @random, @randomt and
@randomct, /r to reply, and /block, /blocklist, /unblock. Lines use
CS2-Tags' rank prefixes and colours: >[[M] Kalus -> me] message. Gagged
players can't send; blocks stop everyone but staff. Messages are kept in
CS2-SimpleAdmin's database while History is on (css_whisper_history).
