Rename Throughput to OperationThroughput, add DataThroughput and DataOperationStats
Reporting changes to support Operation and Data Throughput

Statistics.java - Add JavaDoc for duration time units
HtmlReporter.java - Write tests at the top of report in order added
ReportDocument.java -
   Modify createAndWriteCharts(), createChart(), and addToChart() to
only write a chart if the OperationStats objects provides the
representation requested
   Modify writeOperationHeader() to write correct table header based on
the existence of the throughput
   Modify writeRepresentations() to process OperationThroughput and
DataThroughput objects
TestReportDocument.java - Modify generateChart() to only write a chart
if the OperationStats objects provides the representation requested
Random data and Map/Reduce report

RandomDataStage.java -
   Add statistics for writing, add results for key count, target memory
use, and count of words per node
MapReduceStage.java -
   Add statistics for executing Map/Reduce task
   Add results for number of keys in result map and durations
   Add property to control how many times the MapReduceTask is executed
   Compare the results to make sure they are accurate
AllRecordingOperationStats.java - Modify field access to make it
subclassable
DataOperationStats - New OperationStats class for data operations based
on AllRecordingOperationStats
MapReducer.java - Refactor execute* APIs into configure* and execute*
APIs to allow for statistics gathering in the stage
InfinispanMapReduce.java - Implement MapReducer API changes
Infinispan70MapReduce.java - Implement MapReducer API changes
Report standard deviation for data throughput
Refactor MapReducer interface

Make sure that Infinispan70MapReduce and InfinispanMapReduce.setCombiner
are referenced. (Thanks, Radim!)
Call Statistics.begin() and end() before and after MapTask executions
Update MapReduceStage to put the results in the cache, if the task
doesn't support this
#193 Exclude server acks from ListenersAck list
KeyGenerator, ValueGenerator, and CacheSelector are configured using complex converters
DefineStage: allows defining values that can be reused later in the scenario
Schemas for plugin configuration
* cannot use property-style configuration
* added more fitting service name (rather than just service.default) to plugin.properties
Converters update
Clean shutdown of serialized reporter
* In chart with multiple iterations and cluster sizes, the size goes to category
* Configurable option to disable showing statistics for each node
* Typo fix