Viacom and Charter Communications have agreed to a “short-term” extension of their carriage negotiations and will continue trying to reach a solution that will enable some 16.6 million customers to keep watching MTV, Nickelodeon, Comedy Central and many other networks. A spokesman from Viacom issued a short statement explaining that the company "has agreed to a short-term extension of our renewal deadline with Charter while we work to reach a mutually beneficial deal." A…