Fixes in 1990/jaw

The example commands in the judges' comments had some problems that gave
an error message when running them.

I have also figured out the apparent problem with macOS in the command
under the try section being:

    echo "Quartz glyph jocks vend, fix, BMW." | compress | ./btoa | ./jaw

But it's not actually a problem. It uses perror() and under macOS with
errno == 0 it shows:

    Undefined error: 0

whereas linux shows 'Success'. So it's not actually a problem with the
entry at all. In fact the condition that triggers that call is the same
in both linux and macOS.

I've updated bugs.md to note this and I also updated the README.md to
note it (and to refer to the bugs.md file for more details).

The thank you to me is because I missed it earlier on when I fixed the
scripts, simple though the fixes were.

1990/jaw/shark.sh

@@ -10,7 +10,7 @@ for i in "${@?${usage?$0 file...}}";do<"$i"||exit;done
 # "Cleverly he dialed from within." -- D. Van Vliet, "Trout Mask Replica"
 #
 PATH=$PATH:. a=atob m=unshark z=zcat
-r="rm -f $a $m* $z" v="cc -o $z $m.c"
+r="rm -f $a $m* $z" v="cc -Wno-implicit-function-declaration -o $z $m.c"
 trap "$r;exit 1" 1 2 13 15
 echo decoding...
 (:|compress|./btoa|$a|$z)2>$m>&2||(sed '1,9s/./#define & /
@@ -43,5 +43,5 @@ Z,h@=w;n=8;f=Q+e;i=o=HIo<0)X,1;P(i)WH+1){Iw==Q&e){Z;m=n=8;f=QIH<0)X}
 c=wIw>=f)U++=i,w=oWw>=Q)U++=h@,w=t@;P(i=h@)Wp>D+Q)P(*--p)
 I(w=f)<1l<<k)t@=o,h[f++]=i;o=c}X}
 _
-($v||$v -Mh)&&ln $z $a)&&$a<<\w>$m-&&$z<$m->$m&&tar xvf $m&&$r
+($v)&&ln $z $a)&&$a<<\w>$m-&&$z<$m->$m&&tar xvf $m&&$r
 Z