Add easymock to POMs
Add easymock to SBT configuration.
Refactoring to DAGScheduler to aid testing
Add DAGScheduler tests.
Clear spark.master.port to cleanup for other tests
Refactor DAGScheduler more to allow testing without a separate thread.
Change DAGSchedulerSuite to run DAGScheduler in the same Thread.
Comment at top of DAGSchedulerSuite
Code review changes: add sc.stop; style of multiline comments; parens on procedure calls.
Merge remote-tracking branch 'base/master' into dag-sched-tests

Conflicts:
	core/src/main/scala/spark/scheduler/DAGScheduler.scala
Merge pull request #427 from woggling/dag-sched-tests

Tests for DAGScheduler