Mass typo fixes

This is a HUGE commit:

    417 files changed, 874 insertions(+), 874 deletions(-)

As the IOCCC website now is https enabled I have updated the
'http://www.ioccc' to 'https://www.ioccc'.

There was also a typo in Makefiles where it said 'for VERY WELCOME' when
it should be 'are VERY WELCOME'.

Finally slashdot.org is also https enabled so references to
'http://slashdot' were changed to 'https://slashdot'.

This was done by my sgit tool (see https://github.com/xexyl/sgit)
like:

    sgit -e 's,http://www.ioccc,https://www.ioccc,g' -e 's/for VERY WELCOME/are VERY WELCOME/g' -e  .

but because I didn't have a list of files that should be modified I had
to be careful which files to commit as I had files that were changed but
not ready to be committed. Since I did it in steps, finding typos as I
went along, I actually ran sgit three times but to simplify the above
(and to show that it's possible to do more than one sed command) I made
it all as one. Since I did not have a list of files ahead of time I had
to determine what files to commit, first going through them like:

    for j in $(for i in $(git status|grep modified|cut -d: -f2); do \
	git grep 'https://www.ioccc' "$i"; done|cut -d: -f1|sort|uniq); \
	do git diff "$j"; done|less -r

(I had to pipe through less because of a strange problem with the git
diff which appears to be because of a terminal problem maybe due to the
command above but it was all I could come up with in a very tired head.)

The above and

    git status | grep modified:

showed that some C files had been modified which obviously should not be
done so I had to do:

    git co '*c'

to undo those changes.

Finally to commit the correct files I did:

    for i in $(git status|grep modified|cut -d: -f2); do \
	git grep -E 'https://www.ioccc|https://slashdot|are VERY WELCOME' "$i"; \
	done |cut -d: -f1|sort|uniq|xargs git commit -v

or so (with any formatting issues or typos here due to typos in the log
due to the terminal (in)sanity issue described).

2001/README.md

@@ -12,7 +12,7 @@ You may then wish to look at the Author's remarks for even more details.
 The IOCCC has a web site and now has a number of international mirrors.  The
 primary site can be found at,
 
-     http://www.ioccc.org
+     https://www.ioccc.org
 
 Use make to compile entries.  It is possible that on non-Un\*x / non-Linux
 systems the makefile needs to be changed.  See the Makefile for details.
@@ -83,7 +83,7 @@ email the fix (patch file or the entire changed file) to the above address.
 
 Watch:
 
-	http://www.ioccc.org/
+	https://www.ioccc.org/
 
 for news of the next contest.