One of Dayton's largest insurance brokerage firms is planning for growth in 2015. Brower Insurance, which was acquired by Marsh & McLennan in 2012, has its eye on growth by acquisitions in 2015, after a strong year of organic growth in 2014. That growth could translate to 10 or more new hires in the Dayton office next year. The firm hired 15 new employees between its four offices in the past six months, said President Jeff Lightner. "Acquisitions — that's the big unknown," he said. "I have conversations…