For years one of the many mysteries that has surrounded the annual rounds of that gift giver Santa Claus is, ''How can he travel to all the homes in the world in one night?'' It's simple really, his sleigh is a time machine. Rather than visiting all of the homes in one night, using his time machine he actually works 364 days a year. He takes off December 24, since so many people are up late with final wrapping and inserting flap A into slot B of the toy their child can not live without. But life with a time machine is not a perfect one, especially when you're a convict from the future forced to do the job.