This is a big week for all-everything Houston bassist Nick Gaitan. Not only have his Monday-night Continental Club gigs with atomic-powered rockabilly trio the Octanes been steadily been picking up steam, his other band The Umbrella Man - which just happens to play Tuesday nights at the very same place - releases its self-titled debut CD tomorrow night with special guest Pokey Lafarge. Nick's a busy guy - oh yeah, he also plays bass for Billy Joe Shaver, if you haven't heard - but he was kind e