Implement partial starting of cluster:
- Start HDFS
- Open a shell so you can mess with it
- Terminate HDFS afterwards
Fix parsing of hosts list:
- The old parser wouldn't work because the env variable which it used contained duplicate hostnames under certain circuumstances
- While I was at it, I implemented obtaining of CPU count of each host. We store them in an array and can use them for configuring Hadoop in the future.