[gg582]

Summary

• add persistent per-user /multilingual-route on|off
• route non-ASCII UTF-8 messages to a lazy-created UTF-8 room and non-CP437 legacy input to CP949, CP932, CP936, CP1251, CP850, or CP852 rooms
• keep ASCII and CP437 messages in the current room and preserve the original input encoding across input translation
• tag history entries with backward-compatible room ids and restore created rooms from history
• add /room, /room list, and /room join with eight-language help/messages
• isolate room broadcasts/scrollback and relay only main-room messages to DDial

Tests

• make -j2
• make unit-test
• make SANITIZE=address,undefined unit-test
• cover UTF-8, CP949, CP437, ASCII, room navigation, visibility, history reload, preference reload, and translation route overrides