use rename in stdio to copy config file because boost::copy_file does not support overwritting in old versions
use rename in stdio to copy config file because boost::copy_file does not support overwritting in old versions

izenecloud/izenelib,izenecloud/izenelib,izenecloud/izenelib,pombredanne/izenelib,pombredanne/izenelib,izenecloud/izenelib,pombredanne/izenelib,pombredanne/izenelib