General Motors ended months of speculation by announcing it had sold a 51 percent state in General Motors Acceptance Corp. for what would end up being about $14 billion. But don’t expect any shake-ups with the jewel of GMAC, Residential Capital Corp. any time soon. GMAC officials are saying little about their future with the new controlling owners, Cerberus Capital Management and partner CitiGroup, except that no operational changes are expected, including no layoffs. But…