Make table_lines return tokens after each row.

* This enables huwiki/Vegyületek_összegképlet-táblázata to get
  parsed since it dispatches table row tokens further down the
  pipeline and lets memory get freed in the tokenizer.

  When parsed with --trace html, you can verify that the HTML
  tree builder does get a stream of HTML tokens.

* There is a change to the html2html result of one test. This seems
  to be a result of bad html2wt parsing on the html for the test.
  Here is a snippet of the html2wt result for that test:
    "...|Foo\n|Bar1|}"
  Clearly there is a missing newline before the "|}" which then
  breaks the wt2html parse.

  Till now, we accepted tables with a missing closing tag in
  link captions. But, with this patch, we no longer do. Hence
  the change in html2html result. This patch mimics behavior
  of the PHP parser more closely (which doesn't accept such
  broken tables in link captions either).

Change-Id: I84aab52a04269ce58c274ad3f279600b358e8e14