Included log4j, revised code for classes

Update:
 - fixed doc strings for every methods and classes.
 - added method to read log4j.properties in REEFDriverDelegate.
 - removed doneWithSparkContextInit(),waitForSparkContextInit(), and acquiredSparkContext() 
Why is this part commented out? The method comment states "Notify that..." but there is no actual notification (as far as I can tell)