Update parserTests from upstream; add = and ~ tests.

These new tests pass wt2html and wt2wt, but fail the html2html and html2wt
tests, due to a missing rel='mw:WikiLink' on the <a> tag.  (This issue
causes most parserTests involving links to fail html2html and html2wt.)

Change-Id: I9ce967b66961df1313b065833af0b5accac8352f
Merge "Update parserTests from upstream; add = and ~ tests."