Script to set up a single node pseudo-distributed Hadoop cluster.

This script installs a single node pseudo-distributed Hadoop
cluster following instructions from
http://hadoop.apache.org/docs/r1.2.1/single_node_setup.html
It is useful for tutorial purposes and if one has a decent
machine (say 8 cores, 32G RAM), the installed cluster may be
sufficient for extracting relatively large grammars.