DAYTON, Ohio, March 12 -- The University of Dayton issued the following news: * * * onMain announces stabilization, renovation work on historic Roundhouse onMain Inc. announces the exposition building, better known as the Roundhouse, will undergo a stabilization and exterior renovation project beginning this week. This marks the kickoff of visible work the community will see as onMain begins its innovative redevelopment of the 38-acre site just south of downtown Dayton. The Roundhouse, once   more