Sample mapreduce job - enron email corpus

[mpobrien]

Will build an output collection that looks like this:

{ "_id" : { "t" : "leasa.lopez@enron.com", "f" : "jeff.dasovich@enron.com" }, "count" : 1023 }

Count of how many emails were sent from sender in "_id.f" field to recipient in "_id.t" field.