rem: void DwStrncpy(char* aCstrDest, const DwString& aStrSrc, size_t n)
add: void DwStrncpy(DwString& aStrDest, const DwString& aStrSrc, size_t n)
context: void DwStrncpy(char* aCstrDest, const DwString& aStrSrc, size_t n){    assert(aCstrDest != 0);    const char* buf = aStrSrc.data();    size_t len = aStrSrc.length();    len = DW_MIN(len, n);    mem_copy(buf, len, aCstrDest);    for (size_t i=len; i < n; ++i) {        aCstrDest[i] = 0;    }}