Show "GETTING_RESULTS" state in UI.

This commit adds a set of calls using the SparkListener interface
that indicate when a task is remotely fetching results, so that
we can display this (potentially time-consuming) phase of execution
to users through the UI.
Shorten GETTING_RESULT to GET_RESULT
Merge remote-tracking branch 'upstream/master' into ui_new_state

Conflicts:
	core/src/test/scala/org/apache/spark/scheduler/SparkListenerSuite.scala
Fixed broken tests
Clear akka frame size property in tests
Fixing broken links in programming guide
Merge pull request #105 from pwendell/doc-fix

Fixing broken links in programming guide

Unfortunately these are broken in 0.8.0.
Merge pull request #93 from kayousterhout/ui_new_state

Show "GETTING_RESULTS" state in UI.

This commit adds a set of calls using the SparkListener interface
that indicate when a task is remotely fetching results, so that
we can display this (potentially time-consuming) phase of execution
to users through the UI.