Add the tier 3 utility IRC commands (closes #87)

USERHOST, VERSION, ADMIN, INFO, TIME, KILL and WALLOPS on both the
HTTP API and the IRC listener, and user mode +w.

Model: opus-5-5

internal/db/schema/001_initial.sql

@@ -10,6 +10,7 @@ CREATE TABLE IF NOT EXISTS sessions (
     hostname TEXT NOT NULL DEFAULT '',
     ip TEXT NOT NULL DEFAULT '',
     is_oper INTEGER NOT NULL DEFAULT 0,
+    is_wallops INTEGER NOT NULL DEFAULT 0,
     password_hash TEXT NOT NULL DEFAULT '',
     signing_key TEXT NOT NULL DEFAULT '',
     away_message TEXT NOT NULL DEFAULT '',