By Randall Mikkelsen BOSTON (Reuters) – Grateful Dead lyricist Robert Hunter has dusted off his guitar, practiced five hours a day and polished a repertoire for his first live-performance tour in nearly a decade. Hunter's way with words has earned him a place in the American idiom. "What a long strange trip it's been," from the 1970 Grateful Dead hit "Truckin'," has become a widely used description of life's serendipities. It has also earned him enduring songwriting partnerships with Jerry Garcia, Bob Dylan and others. …