SHANGHAI/BEIJING (Reuters) - China's plans to introduce real estate investment trusts (REITs) mark a crucial step to get private money to fund infrastructure such as toll roads and sewage systems, but authorities have their work cut out in creating a fully-fledged market.In many countries REITs are used as a means for investors to own property via the stock market, enjoying the income from projects such as tenanted office blocks, while allowing developers to free up their balance sheets for new..