Implement a heuristic to strip <nowiki/> in some quote scenarios

* When <i> and <b> tags are matched up properly on a line, any
  quote char that precedes a <i> or <b> tag does not need to be
  protected with a <nowiki/>.

* Since this is hard to do without a full-line context, the
  <nowiki/> is stripped after the fact by examining the current
  line of serialized output.

* Lets us get rid of a few <nowiki/> copies of parser tests and
  fixes some failing tests.

Change-Id: I81d15ecce888f6e0104fb089329a9db77828d86c
Merge "Implement a heuristic to strip <nowiki/> in some quote scenarios"