LONDON, Dec 13 (Reuters) - Global news agency Reuters (RTR.L: Quote, Profile , Research) on Wednesday appointed David Schlesinger to be its new editor in chief, replacing Geert Linnebank, who will become a senior adviser to the company's chief executive. Schlesinger, who has been global managing editor and head of editorial operations since 2003, will take over in January 2007. "He (Schlesinger)...