Bug 50483: Make sure nested list serialization is newline-insensitive

* Fixed a long-standing bug in nested list serialization that caused a nested
  list to end up on the same line as its wrapping list item:

echo '<ol><li>Foo<ol><li>Bar</li></ol></li></ol>' | node js/tests/parse.js
--html2wt

* Added a Parsoid-specific test case to ensure that newline-less HTML
  serializes with the proper newline constraints

* Updated the blacklist as some more selser tests are now passing.

Change-Id: I8d92b72d81f0330126a34601874cb2c62763fde5
Merge "Bug 50483: Make sure nested list serialization is newline-insensitive"