Target is navigating turbulent economic times by polishing old stores rather than opening new ones and seeking growth in countries outside of the United States, such as  Mexico. The discount chain said yesterday that it will spend $1 billion renovating 340 stores while opening fewer than 10 new ones in 2010. That's dramatically fewer than the 58 it opened in the fiscal year ending Jan. 31 and the 91 it opened in fiscal 2008. The renovated stores will also offer more groceries. The...