bitlbee-facebook top automatically set room name from topic

[kflu]

When A new message arrives in a group chat, a room with name chat_xxx appears. There can be so many of them, its hard to distinguish.

Can it automatically set the room name from the topic? E.g., if topic is "this is a group chat", then room name "#this_this_a_group_chat". We can:

1. escape invalid characters
2. chop of long strings