LONDON/ANTANANARIVO (Reuters) -The Madagascan president's chief of staff has been arrested in London on suspicion of seeking a bribe from precious stone miner Gemfields and removed from her post, British and Madagascan authorities said on Monday. Britain's National Crime Agency (NCA) said Romy Andrianarisoa, 46, and a French associate Philippe Tabuteau, 54, were detained at a meeting in London where they were believed to have sought a bribe to secure licences to operate in Madagascar. A lawyer f