Sync parserTests with core.

This matches upstream commit 9b22f7bc26f770e339bd9fa6b3542c84bb7723eb.

New tests were added for the following Parsoid bugs, all of which currently
fail:

* Bug 52762: ignore lines with nothing but two-or-more comments
* Bug 52760: close tags are stripped (found in test for bug 17663)
* Bug 52363: bare pipes
* Bug 52761: preformatted in <blockquote> (should be parsed like <div>)

In addition, a number of new tests were added for preprocessor magic
words (gerrit change I79023a1585f92be6c0cea13a462ae091a60838d3) which
aren't currently supported by Parsoid's preprocessor implementation.

Change-Id: I3a06fbce0858507ac86e1832e7cf3456cfda1da4
Merge "Sync parserTests with core."