Mass .gitignore update for .orig.c files

Due to the fact we now have .orig.c files and thus the possibility of
winner.orig or prog.orig being built I have updated all the .gitignore
files so that these files ignored. This was done with the following
shell commands, for reference:

    for i in $(find 19* 200* 201[0123] -mindepth 2 -maxdepth 2 -name .gitignore) ; do echo $(dirname "$i"|sed -e 's,[0-9]\{4\}/,,g').orig >> "$i"; done
    for i in $(find 201[4-9] 2020 -mindepth 2 -maxdepth 2 -name .gitignore) ; do echo prog.orig >> "$i"; done

and the two commands is because it was only in 2014 that the winning
entries were renamed to prog so prog.orig is the correct glob.

1996/august/.gitignore

@@ -6,3 +6,5 @@ parse.oo
 prog.oc
 august.oo
 prog.oo
+august.orig
+prog.orig

1996/dalbec/.gitignore

@@ -1 +1,3 @@
 dalbec
+dalbec.orig
+prog.orig

1996/eldby/.gitignore

@@ -1,2 +1,4 @@
 eldby
 eldby.alt
+eldby.orig
+prog.orig

1996/gandalf/.gitignore

@@ -1,3 +1,5 @@
 cathat
 gandalf
 hatcat
+gandalf.orig
+prog.orig

1996/huffman/.gitignore

@@ -1 +1,3 @@
 huffman
+huffman.orig
+prog.orig

1996/jonth/.gitignore

@@ -1 +1,3 @@
 jonth
+jonth.orig
+prog.orig

1996/rcm/.gitignore

@@ -1 +1,3 @@
 rcm
+rcm.orig
+prog.orig

1996/schweikh1/.gitignore

@@ -1 +1,3 @@
 schweikh1
+schweikh1.orig
+prog.orig

1996/schweikh2/.gitignore

@@ -1 +1,3 @@
 schweikh2
+schweikh2.orig
+prog.orig

1996/schweikh3/.gitignore

@@ -1 +1,3 @@
 schweikh3
+schweikh3.orig
+prog.orig

1996/westley/.gitignore

@@ -1,2 +1,4 @@
 westley
 westley.alt
+westley.orig
+prog.orig