The Parks Dept. decided to throw in the towel on litigation that's been going on for three years and conceded to reevaluate its requirement that no more than 50,000 people could gather on Central Park's Great Lawn at one time. Aside from six allotted exceptions (per year) that include four reserved for performances by the Metropolitan Opera and the NY Philharmonic, the city's rationale for crowd-size restrictions was that very large crowds could damage the......