(defendant charged with various criminal violations of state hunting laws based initially on discovery of game feeder and salt-block viewed by state game officials from airplane; defendant moved to suppress evidence based on Fourth Amendment; trial court's denial of defendant's motion upheld because "search" was merely an innocent observation of defendant's property and not a "search" as contemplated by the Fourth Amendment; defendant's posting of property insufficient to shield any and all observation of items not shielded or protected from view from places exterior to the property).