fix many internal links

Fixed a number of internal links that need to
go to the GitHub site.

Ran `make www` to perform the above.

2013/cable3/index.html

@@ -445,7 +445,7 @@ and somewhat useless beast. For everyone else, please run the emulator on a
 little endian machine.</p>
 <h3 id="rule-2-abuse-disclaimer">RULE 2 ABUSE DISCLAIMER</h3>
 <ul>
-<li><a href="cable3.c">cable3.c</a> is 4043 bytes in length (half an 8086).</li>
+<li><a href="https://github.com/ioccc-src/temp-test-ioccc/blob/master/2013/cable3/cable3.c">cable3.c</a> is 4043 bytes in length (half an 8086).</li>
 <li><code>iocccsize -i &lt; cable3.c</code> returns 1977 (the year the 4.77 MHz 8086 CPU was announced)</li>
 <li>Therefore, any suspicions the judges may have regarding rule 2 non-compliance
 might be well-intentioned but are groundless.</li>