Format 2013/dlowe, new script, rename others etc.

The demo.sh was renamed try.sh to be like the other entries.

The new script diff.sh runs some commands that I had previously added
(to demonstrate the entry) but which would be better in a script.

Renamed sflen.sh (for sparkline file length) to be slflen.sh (for
sparkline file length also).

Updated bugs.md - added more features that the author noted.

Format/typo check README.md file.

This should complete the review of 2013/dlowe.

2013/dlowe/diff.sh

@@ -0,0 +1,22 @@
+#!/usr/bin/env bash
+#
+# 2013/dlowe/diff.sh - show diff of output of two commands based on different
+# number of files (due to total length differing) in the directory
+
+# make sure CC is set so that when we do make CC="$CC" it isn't empty. Doing it
+# this way allows us to have the user specify a different compiler in an easy
+# way.
+if [[ -z "$CC" ]]; then
+    CC="cc"
+fi
+make CC="$CC" all >/dev/null || exit 1
+
+echo "$ ./try.sh | tail -n 3 > 1.txt" 1>&2
+./try.sh | tail -n 3 > 1.txt
+echo "$ echo 'IOCCC winning entry 2013/dlowe' > ioccc.txt" 1>&2
+echo 'IOCCC winning entry 2013/dlowe' > ioccc.txt
+echo "$ ./try.sh | tail -n 3 > 2.txt" 1>&2
+./try.sh | tail -n 3 > 2.txt
+echo "$ diff 1.txt 2.txt" 1>&2
+diff 1.txt 2.txt
+rm -f 1.txt 2.txt ioccc.txt