Hadoop EC2 scripts broken on Windows / cygwin

Grrr... As of 0.21.0, the list-hadoop-clusters and delete-hadoop-cluster scripts need the rev utility, which is neither installed by default nor available as an add-on (unless I'm braindead, which is a definite possibility).

Quickfix : use tac instead

$ ln -s /bin/tac /bin/rev

Fugly, but now the scripts work...