/**
* 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;
}