(Bug 50447) Quote balancing should not cross td/th boundaries

* Quote balancing should be done within the context of td/th
  cells rather than crossing over those boundaries even when
  said wikitext is on a single line.

* Added parser tests (and updated blacklist for failing wt2wt
  test -- because of autoInserted closing tags)

Change-Id: I5ad48ce2b0097ecee8f0ffe7d26aab2aa9f068e7