FileUtil.cc: Use TextUtil instead of StringUtil for ToUpper & ToLower functionality
FileUtil.cc: Use TextUtil instead of StringUtil for ToUpper & ToLower functionality

ubtue/ub_tools,ubtue/ub_tools,ubtue/ub_tools,ubtue/ub_tools,ubtue/ub_tools,ubtue/ub_tools,ubtue/ub_tools,ubtue/ub_tools