Made changes to the SparkContext to have a DynamicVariable for setting local properties that can be passed down the stack. Added an implementation of the fair scheduler
Changed the name of the system property to set the allocation xml
Updated/Refactored the Fair Task Scheduler. It does not inherit ClusterScheduler anymore. Rather, ClusterScheduler internally uses TaskSetQueuesManager that handles the scheduling of taskset queues. This is the class that should be extended to support other scheduling policies
Cleaned up the code
Removed some commented code