This week we look at all-Beatles radio, yesterday and today.     Over thirty years ago, tiny Texas City AM station KYST changed formats to become the first all-Beatles station in the country.      MAnagement couldn't have had too much faith in the format, as they never filed the paperwork or paid the fee to officially change their call letters to KBTL.      We compare and contrast that version of the format with the Beatles-backed Sirius XM implementation that launched May 18.