* Soy, corn post weekly losses after USDA data, mild weather * Wheat bounces after multi-month lows, but ends week down * CBOT closed Friday, reopens Monday at 8:30 a.m. CDT/1330 GMT (Updates with closing prices) By Julie Ingwersen CHICAGO, July 3 (Reuters) – U.S. soybean futures fell on Thursday, retreating from early gains as