Nowiki wrap new text w/ pre|post-apost. adjacent to i|b

 * When an apostrophe is added to the beginning or end of a text-node
   next to an italic or bold element, it can serialize to unintended
   semantics. Ex.

     <p>New text goes'<i>here</i></p>

         --> New text goes'''here''
     now --> <nowiki>New text goes'</nowiki>''here''

 * The newly failing selser tests are precisely these scenarios.

Bug: 52784
Change-Id: I02087c217da2ab4fc113d336d689a657275cb834
Merge "Nowiki wrap new text w/ pre|post-apost. adjacent to i|b"