Made ordinary and fast ASCII readers store comments in Table .meta

This is meant to address #3136.
Actually `comment_lines` is at the top level of the Table's .meta:
```
In [8]: t = ascii.read(['#comment', 'a,b,c', '1,2,3'])

In [9]: print t.meta['comment_lines']
['#comment']
```
This is because `TableOutputter` uses `meta['table']` rather than the entire `meta` to pass to the Table it creates--not sure why though.