Remove almost all absolute URLs for this site

In a number of cases, an absolute URL for www.ioccc.org
was replaced with a document root relative URL.

In some cases the absolute URL was removed.

Removed mirror request pages.

2018/burton2/hint.html

@@ -42,7 +42,7 @@
 
 <h3>Selected Judges Remarks:</h3>
 
-<p>They say size isn&rsquo;t everything, and in the case of IOCCC <a href="http://www.ioccc.org/2018/iocccsize.c">iocccsize.c</a>
+<p>They say size isn&rsquo;t everything, and in the case of IOCCC <a href="/2018/iocccsize.c">iocccsize.c</a>
 that is saying something!  What is this program weighing and how much does it weigh?</p>
 
 <h2>Author&rsquo;s comments:</h2>