make wise m/r job read last ten minutes of data

This changes the Wise map/reduce job, not to use a dataset to keep track of when it last ran. Instead, because this mr is run every 10 minutes as part of a workflow schedule, it will always read the last ten minutes leading up to the logical start time of the workflow. 

I think this is nicer because it simplifies the app and it also illustrates the getLogicalStartTime() feature of the MR context.