Add name for main threads and handle broken pipe on broadcast
Add name for main threads and handle broken pipe on broadcast

I added names on the connection-handler thread and message-broadcast.
This can keep more easily to debug later.

Treat exceptions of type sb-int:simple-stream-error when try propagate
messages from clients. If someone fails by this error, delete the client.
Buggy clients shall no mercy!

ryukinix/lisp-chat,ryukinix/lisp-chat