(Bug 52035) Dont get tripped by " :" tokenizer hack in nowiki escaping

* It looks like we have to preserve the display of the single-space
  before ":" to mimic display requirements and what the PHP parser
  does.  So, the tokenizer wraps that single space in a placeholder
  span and adds an entity (not sure if this is the best solution).

* Since the nowiki escaper occasionally relies on the tokenizer to
  detect escaping scenarios, it got tripped by the placeholder token
  and assumed that a non-string tokenization of "foo bar :"  implied
  that the string had to be nowiki escaped.

* Fixed the tokenizer to add a flag so the nowiki escape can find
  the flag and ignore the token.

* Fixes the new parser test added to parserTests.txt
  echo "<p>foo's bar :</p>" | node parse --html2wt

Change-Id: I589b7def201811f9dcc4770718b705a51c567723
Merge "(Bug 52035) Dont get tripped by " :" tokenizer hack in nowiki escaping"