Fix more typos, primarily in the code

The only visible change is that git-blame doesn't understand
"--compability" anymore, but it does accept "--compatibility" instead,
which is already documented.

Signed-off-by: Pavel Roskin <proski@gnu.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
diff --git a/git-merge-one-file.sh b/git-merge-one-file.sh
index 5619409..fba4b0c 100755
--- a/git-merge-one-file.sh
+++ b/git-merge-one-file.sh
@@ -8,7 +8,7 @@
 #   $2 - file in branch1 SHA1 (or empty)
 #   $3 - file in branch2 SHA1 (or empty)
 #   $4 - pathname in repository
-#   $5 - orignal file mode (or empty)
+#   $5 - original file mode (or empty)
 #   $6 - file in branch1 mode (or empty)
 #   $7 - file in branch2 mode (or empty)
 #