/**
*  Renames a file (Source file will be deleted!)
*  @param   oldname
*           newname
*  @requires WINDOWS (because fcopy does)
*/
stock frename(oldname[],newname[]) {
    if (!fexist(oldname)) return false;
    fremove(newname);
    if (!fcopy(oldname,newname)) return false;
    fremove(oldname);
    return true;
}