implement FIFO and fair scheduler for spark local mode
1. Add unit test for local scheduler
2. Move localTaskSetManager to a new file
change code style and debug info
Update LocalSchedulerSuite to avoid using sleep for task launch
Merge remote-tracking branch 'xiajunluan/xiajunluan'

Conflicts:
	core/src/main/scala/spark/scheduler/cluster/TaskSetManager.scala