Merge pull request #7 from gravyboat/master

Bumped licenes, fixed readme formatting.
fixed requisites
fixed more requisites
added apache hadoop-2.3.0
removed all includes in favor of overstate
number of mapreduce dfs replicas is now configured by salt (defaults to 10), added configuration of dfs.hosts and dfs.excludes to allow later decommissioning
unrequire hadoop group in the user macro
exclude hadoop user subdirectories in the user macro for now
added defs for CDH 4.6.0