Added more recent Hadoop
Added master and slaves as parameters for the module

Added group = hadoop to the namenode format, seen some people having
issues if group isn't passed

Added File["hdfs-dir"] as a require for namenode format, and removed
File["java-app-dir"] from the same.
Changed parameters according to the recommendations done by biemond

Added a direct java_home instead of relying on another module
Updated the hadoop version to 1.1.1
Added "" around the slaves default names to properly work
Added .gitignore for the ssh files
Removed ssh files