* NAMES and WALLOPS command
* -cloak option
* -v renamed to -verbose
* -passwords renamed to -passwd
* -debug option prints traffic messages
* without -verbose only startup/shutdown and error messages are printed
* -timestamped option provides timestamps in printed messages, as
earlier. No timestamps is useful for running under daemontools
* passwords are stored in SHA256-hashed format
* state files replaced with state directory with files
* removed many unnecessary pointers and locks
* graceful shutdown with all clients notification
* fixed time structure printing in log files, instead of short human
readable timestamp
* PART is sent to the user itself, to notify his client about leaving
* log messages are printed to stdout, instead of stderr, for
friendliness with daemontools logger
* ability to configure newly created directories and files with
-perm-state-dir, -perm-state-file, -perm-log-file
Simplify code and server maintaining by removing password file caching
and refreshing it with HUP signal. Also use pointers to strings, already
presented after flag-module work.