FMSLogo Code

Integrate a Chess game contributed by Alexandar Vezo
https://sourceforge.net/p/fmslogo/discussion/500407/thread/f69f304933/

Upstream Source: https://github.com/AlexVezo/FMS-Logo-Chess

Silence the warnings about "NT" appearing in the documentation for SHELL.
This is due to a recent change that uses "Windows NT" in a file path.

Fix Bug #595; GENSYM now buries the variable "gensym.number", as UCBLogo does.
Also, update the help entry for GENSYM to clarify this behavior.

Add a reminder to upload files in the "media" directory.
I had forgotten to do this when I added some new screenshots and the <img> has been broken since.

Rewrite the instructions for tagging, now that I no longer have the svn root checked out as a working copy.

Tagging source code used to build FMSLogo 8.4.0

Add the result of the 8.4.0 test pass.

Update the results with the third run from the 8.4.0 test pass (after fixing a regression)

Fix a regression that stopped SETTIMER from working in the screensaver.
The problem is that there were two #if with only one #else, so the timer events never fired on their own.
This regression was not included in any official release.

Update the results with the second run from the 8.4.0 test pass (after a small fix to the test code)