move fix thanks a file, update top level html links, rename CONTRIBUTING.md

The fix thank you's have been moved from `README.md` to
`thanks-for-fixes.md`.

**WARNING**: Some mistakes may have been made in doing this.
We presume later changes by others will correct any issues.

The `CONTRIBUTING.md` was renamed `how-to-enter.md`.

A 3rd line of links was added to top level html such as
`contact.html`, `index.html`, `judges.html`, `winners.html`,
and `years.html`.

Improved blank line use in a number (but not all) `README.md` files.

winners.html

@@ -7,19 +7,27 @@
 </HEAD>
 <BODY TEXT="#000000">
 
-<CENTER><IMG ALT="IOCCC" SRC="png/ioccc.png"></CENTER><BR>
+<CENTER><a HREF="2011/zucker/hint.html"><IMG ALT="IOCCC" SRC="png/ioccc.png"></a><br><FONT SIZE="1">Logo by winner <a href="2011/zucker/hint.html">Matt Zucker</a></font></CENTER><BR>
 <CENTER><FONT SIZE="6"><I>The International Obfuscated C Code
 Contest </I></FONT></CENTER><BR>
-<CENTER><P>[ <A HREF="judges.html">The judges</A> |
-<A HREF="main.html">IOCCC home page</A> |
-<A HREF="main.html#enter">How to enter</A> |
+
+<P>
+<CENTER>
+<A HREF="judges.html">The judges</A> |
+<A HREF="index.html">IOCCC home page</A> |
 <A HREF="faq.html">FAQ</A> |
+<A HREF="index.html#enter">How to enter</A> |
 <A HREF="contact.html">Contacting the IOCCC</A>
-<BR>
-<A HREF="main.html#new">IOCCC news</A> |
+<BR><BR>
+<A HREF="index.html#news">IOCCC news</A> |
 <B>People who have won</B> |
-<A HREF="years.html">Winning entries</A> ]</P></CENTER>
-<BR>
+<A HREF="years.html">Winning entries</A>
+<BR><BR>
+<A HREF="bugs.md">Known Bugs &amp; (Mis)features</A> |
+<A HREF="how-to-bugfix.md">How to fix an IOCCC winner</A> |
+<A HREF="thanks-for-fixes.md">Thanks for the fixes</A> |
+<A HREF="www-history.md">A bit of web site history</A>
+</CENTER>
 
 <CENTER><P>[
 <A HREF="winners.html#A">A</A>&nbsp;&nbsp;