FARNBOROUGH, England (Reuters) – Airbus and Boeing head into next week's Farnborough Airshow locked in their fiercest market share battle for up to a decade, slashing prices to win key orders for their latest narrowbody jets and storing up potential trouble for future profit margins. From Australia to Indonesia, the United States to Norway – and most recently, Reuters has learned, Turkey – the marauding plane giants have spent months taking or defending market share, with world No.1 Airbus aiming deep inside Boeing's territory and its rival publicly vowing to defend a traditional 50-50 split. …
