* Jan-Feb property investment rose 11.6 pct y/y, quickens from 2018.: BEIJING, March 14 (Reuters) - China’s property investment accelerated in the first two months of the year driven by strong demand in its hinterland and defying a decline in sales, government curbs in bigger markets and a broader economic slowdown. Real estate investment, which mainly focuses on the residential sector but also includes commercial and office space, is a key driver of growth for the world’s second-largest economy.