Renamed StandaloneX to CoarseGrainedX.

The previous names were confusing because the components weren't just
used in Standalone mode -- in fact, the scheduler used for Standalone
mode is called SparkDeploySchedulerBackend. So, the previous names
were misleading.
Added back fully qualified class name
Unified daemon thread pools
Merge remote branch 'upstream/master' into rename
Fixed build error after merging in master
Merge pull request #61 from kayousterhout/daemon_thread

Unified daemon thread pools

As requested by @mateiz in an earlier pull request, this refactors various daemon thread pools to use a set of methods in utils.scala, and also changes the thread-pool-creation methods in utils.scala to use named thread pools for improved debugging.
Merge pull request #34 from kayousterhout/rename

Renamed StandaloneX to CoarseGrainedX.

(as suggested by @rxin here https://github.com/apache/incubator-spark/pull/14)

The previous names were confusing because the components weren't just
used in Standalone mode.  The scheduler used for Standalone
mode is called SparkDeploySchedulerBackend, so referring to the base class
as StandaloneSchedulerBackend was misleading.