Fix typos in txt2html

  <LI> "}" (right bracket) --&gt; turn-off italics by 

    inserting a &lt;/I&gt; </UL>

<P>If a backspace '\' preceeds any of the bold/italic mark-up characters,

<P>If a backspace '\' precedes any of the bold/italic mark-up characters,

then mark-up is not performed; the mark-up character is simply left in

the text.

</P>

  string punctuation = ".,?!;:()";

  // substitute for bold & italic markers

  // if preceeded by \ char, then leave markers in text

  // if preceded by \ char, then leave markers in text

  n = s.find_first_of("[]{}");

  while (n != string::npos) {