The Democratic convention is shaping up into a potential brawl. Last week Ned Lamont, the Greenwich millionaire who lost the 2006 US Senate race to Joe Lieberman, announced that Mary Glassman, the Simsbury first selectman, would be his running mate as lieutensnt governor candidate. Democrats are saying that Malloy’s big news conference tomorrow at the Capitol will unveil state Comptroller Nancy Wyman as his partner in politics.