Carl Icahn, one of America's most relentless shareholder activists, celebrated his 71st birthday Feb. 16. The party: He launched another proxy battle, this time for control of Bonita Springs-based WCI Communities Inc.Icahn in recent months has acquired nearly 15% of the homebuilder's shares. He wants to replace the entire board of WCI with his own slate of directors, including himself and Hugh Culverhouse Jr., owner of Sarasota-based Palmer Ranch and son of the late Tampa Bay Buccaneers' owner, who, in his day, waged his own share of takeover battles.