Try only to make performant server on non-Windows
Revert "Try only to make performant server on non-Windows"

This reverts commit d9e207816e24292126a37fd188969cf94d9afd4d.
Make server sleep for the proper time when no player is connected (fixes master server registration on Windows)
Version 6.6.4
Player can be NULL, prevent crashes
Add hook duration tune
Always call freeaddrinfo
Remove unused members
Merge branch 'DDRace64' of github.com:def-/ddnet into DDRace64