With its frontman Randy Blythe  still sitting in a jail cell in Prague, Lamb of God on Thursday announced the cancellation of its upcoming tour.  The 41 year-old singer has been charged with manslaughter in connection with the death of a fan at a 2010 Lamb of God concert, and remains in custody despite paying $400,000 in bail last week.  Prior to his release, prosecutors challenged his bail, and a judge is set to rule on that challenge soon.  The tour was slated to kick off next Wednesday in Seattle, but the band announced the cancellation on its official website, citing "uncertainty" surrounding Blythe's release.  Full refunds will be available for fans with tickets to any of Lamb of God's canceled shows.