word . not working well

Try this code, it is not working (Firefox 52):
```: FOO DUP + ;
42 FOO .
```
and will print `<ok>` instead of `84 <ok>` while this code works:
```: FOO DUP + ;
42 FOO
.
```
and will print `84 <ok>`

With the same idea:
```: FOO DUP + ;
42 FOO . .
```
will not produce a stack underflow.

Still the same idea:
```42 DUP . .``` will only consume and display 1 element
