Crosstable fix

I think I fixed the issue describe for 1D table

```
> pander(descr::CrossTable(mtcars$am))

--------------------------
 &nbsp;   0    1    Total 
-------- ---- ---- -------
  N\     19\  13\   32\   
Row (%)  59%  41%   100%  
--------------------------
```

Also, while working on it, I realized that with other changes, rendering of `CrossTable` was not entirely correct. Problem was that `format` was adding trailing spaces, which negative affected table width calculation. I also removed that with, and it should not affect any other cases.