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!

2015/yang/README.md

@@ -28,7 +28,7 @@ The way the text is encoded in the output doesn't cease to amaze. Can you tell
 why an array of 512 elements is needed?
 
 NOTE: the author calls the program `Fuuko` and so the source file referred to in
-their remarks uses `fuuko.c`. The [Makefile](Makefile) will compile everything
+their remarks uses `fuuko.c`. The [Makefile](%%REPO_URL%%/2015/yang/Makefile) will compile everything
 so you need not worry about this.