WASHINGTON (Reuters) -U.S. single-family homebuilding and permits for future construction dropped in August amid a glut of unsold new houses and a softening labor market, shrugging off falling mortgage rates. Single-family housing starts, which account for the bulk of homebuilding, fell 7.0% to a seasonally adjusted annual rate of 890,000 units last month, the Commerce Department's Census Bureau said on Wednesday. Permits for future single-family homebuilding decreased 2.2% to a rate of 856,000 units. Th ...