fix topbar to work on mobile devices

The topbar, by way of JavaScript, now works
on mobile devices such as cell phones and
tablets.

Internal links for entries from 1984 thru 2015
have been adjusted.

Ran `make www` to perform the above.

TODO: Fix some color issues on topbar.

TODO: More testing!

2018/bellard/README.md

@@ -17,7 +17,7 @@ code](#alternate-code) below.
 
 ## Try:
 
-First open [Lenna.png](Lenna.png) in your graphics viewer of choice. Next, after
+First open [Lenna.png](%%REPO_URL%%/2018/bellard/Lenna.png) in your graphics viewer of choice. Next, after
 running the above command (`./prog > lena.ppm`), open `lena.ppm` in your
 graphics viewer of choice.  After that try:
 
@@ -32,13 +32,13 @@ compile and install netpbm for entries that require it?](../../faq.html#netpbm)
 [FAQ 3.16 - How do I compile and install libjpeg-turbo for entries that require
 it?](../../faq.html#libjpeg).
 
-NOTE: [Lenna.png](Lenna.png) is from
+NOTE: [Lenna.png](%%REPO_URL%%/2018/bellard/Lenna.png) is from
 <https://upload.wikimedia.org/wikipedia/en/7/7d/Lenna_%28test_image%29.png>.
 
 
 ## Alternate code:
 
-The [prog.alt.c](prog.alt.c) is based on the author's remarks and it should work
+The [prog.alt.c](%%REPO_URL%%/2018/bellard/prog.alt.c) is based on the author's remarks and it should work
 for Windows.