Improve performance, use SplDoublyLinkedList for lists (2x as fast)
Also features O(1) inserts, so it doesn't slow down as the lists grow
Add Server::getLocalAddress() to return the listening address
Support binding to a random port (0 port) and adjust tests
This makes sure to not fail if the previous port 1337 was already in use
Remove leftover default address
Add $debug option (which now defaults to false)
Add LINDEX command