chatd prints received message via telnet
Ignore chat/chatd
Add user_manager
delete user when connection closed
Add safe_strdup
Add message_queue
Add safe_epoll_ctl1
Add receive_message
Add safe_getaddrinfo
Use designated initializer
Support IPv4/IPv6 dual stack
Add timestamp to message
Add copy_message
Add safe_read, safe_write
Add message format

HH:MM:SS sender_name: body
Add user_t->state
Extract create_connection
Fix: remove trailing CRLF which telnet sent
Support receiving messages depending on user->state
Fix: free user->name only when allocated