After a laborious two-year overhaul beset by delays, cost overruns and unforeseen problems, Navy officials said Monday that the military's oldest nuclear-powered aircraft carrier is once again ready for war. The 49-year-old Enterprise, which has been docked at Northrop Grumman's Newport News shipyard since April 2008, was originally slated to return to service six months ago. That plan changed after repair crews discovered damage and decay - from rotted pipes to fried electronics - far beyond what they'd anticipated. As the list of repairs grew, so did costs, to nearly $700 million from an initial estimate of $450 million. That's...