added new tile n3w5
added new tile n4w5
added description and leave for east (n4w5)
changed description for leave W/S/N function
added challenge (n3w5)
added reply in the riddle in action (n3w5)
added else on action
added take_knife function (n3w5)
added leave function (n3w5)
removed leave restriction for west (n3w4)