Reword the recent deobfuscation changes

In most cases the word was changed to 'obfuscation' as it was about
obfuscation, not deobfuscation. In some cases like 1995/leo since the
file was (in 1995/leo) about a secret switch it was changed to
'secret.md' (and 'secret.html') but there were others like that as well.

One entry had the words 'spoiling the size rule' but this had been
changed to 'deobfuscating the size rule' which was obviously wrong.

In the latter YYYY/README.md files the judges had written after some
entries (brief summaries) '...

    ...We'll stop spouting spoilers now. Have fun exploring all the
    entries!

but that was changed to:

    ...We'll stop spouting deobfuscation information now. Have fun
    exploring all the entries!

which wasn't really about deobfuscation but just a brief summary of what
the entries did.

And in the most problematic case (at least for me :-), 2018/ferguson) I
had put a joke in:

    ... but it's the only Easter egg I won't spoil

but it was changed to 'won't deobfuscate' which not only is not what it
is but it spoilt the joke.

In some cases the word was changed back to 'SPOILER' (or similar) but in
most cases not. I believe it should be better now. There are some
caveats, however, as below.

Although make find_missing_links is okay I do not remember if this will
catch links that refer to '%%REPO_URL%%' or other pandoc tokens. This
means I might have to go back to some earlier years to verify links are
okay. That should not take that much time I hope.

It might also be that some wording can still be improved some but it is
hoped this will be discovered when checking links and looking over the
manifest (which obviously changed).

2018/ferguson/README.md

@@ -117,7 +117,7 @@ If you find yourself in an evolutionary dead end, try:
 0. Preface
 1. What it is
 2. How it works
-3. Hints (Keyboards, Options, Deobfuscation, Example Invocations)
+3. Hints (Keyboards, Options, Obfuscation, Example Invocations)
 4. Obfuscation (Techniques, Beauty)
 5. How to build (S and N Constants, Compilation, Portability, Installing)
 6. Final thoughts
@@ -125,10 +125,10 @@ If you find yourself in an evolutionary dead end, try:
 
 ## **0. Preface**
 
-**DEOBFUSCATION NOTES: A great deal of this document and the man page is full of
-deobfuscation information of different types; as such I would recommend that you try running the
+**OBFUSCATION NOTES: A great deal of this document and the man page is full of
+obfuscation information of different types; as such I would recommend that you try running the
 judges suggested invocations as well as running `make test` before you get into
-the document or the man page, unless you don't mind reading deobfuscation information. I don't reveal
+the document or the man page, unless you don't mind reading obfuscation information. I don't reveal
 much in the way of obfuscation however so if you just want documentation on the
 program, how to compile, etc. then there isn't need to heed this note.**
 
@@ -263,7 +263,7 @@ try and show the way they work) for those interested I will cite the summary:
     the fittest individuals dominating over the weaker ones.
 ```
 
-**DEOBFUSCATION NOTE: Some of the below might help you follow the code more
+**OBFUSCATION NOTE: Some of the below might help you follow the code more
 easily.**
 
 For each *generation* there is a total of `N` *offspring*; generation 0 is
@@ -387,7 +387,7 @@ can actually produce but there is a certain type of input error that might
 ### Options
 </div>
 
-Skip to the [deobfuscation section](#deobfuscation).
+Skip to the [obfuscation section](#obfuscation).
 
 There are a number of options you can pass to the program besides the target
 string; some I will document here (the summary being in the man page). You can
@@ -453,7 +453,7 @@ decent parameters - come to an answer here but if necessary kill the program.
 
 4. Repeat the steps only this time don't enable quiet mode. Look at the
 offspring output. If you still don't see what it is and want to know see
-**[Deobfuscation information](#deobfuscation)** below.
+**[obfuscation information](#obfuscation)** below.
 
 Finally any argument that doesn't start with a `-` passed into the program
 will become the target string. The same rule applies to the number for `-r`:
@@ -558,8 +558,8 @@ it no longer cares about the `-` for option parsing. In other words options
 are only parsed if the first character is `-` and if the parser hasn't seen
 the `-` - *in an earlier element of `argv`. This is not a bug!*
 
-<div id="deobfuscation">
-### Deobfuscation
+<div id="obfuscation">
+### Obfuscation
 </div>
 
 Skip to [Example Invocations](#invocations).
@@ -981,7 +981,7 @@ implementation of the Weasel program otherwise).
 There is obviously a reason `38` is the chosen size but the only hints I
 provide are those in **[How it works](#how)** and specifically an Easter egg I
 referenced there (it's *not the only Easter egg* but it's the only Easter egg I
-won't deobfuscate; yes this ironically and amusingly means I've left a rotten egg
+won't spoil; yes this ironically and amusingly means I've left a rotten egg
 somewhere!).
 
 The Makefile simplifies how to reconfigure this value with the variable