[SPARK-4264] Completion iterator should only invoke callback once

Author: Aaron Davidson <aaron@databricks.com>

Closes #3128 from aarondav/compiter and squashes the following commits:

698e4be [Aaron Davidson] [SPARK-4264] Completion iterator should only invoke callback once
[SPARK-4249][GraphX]fix a problem of EdgePartitionBuilder in Graphx

at first srcIds is not initialized and are all 0. so we use edgeArray(0).srcId to currSrcId

Author: lianhuiwang <lianhuiwang09@gmail.com>

Closes #3138 from lianhuiwang/SPARK-4249 and squashes the following commits:

3f4e503 [lianhuiwang] fix a problem of EdgePartitionBuilder in Graphx
[HOT FIX] Make distribution fails

This was added by me in https://github.com/apache/spark/commit/61a5cced049a8056292ba94f23fa7bd040f50685. The real fix will be added in [SPARK-4281](https://issues.apache.org/jira/browse/SPARK-4281).

Author: Andrew Or <andrew@databricks.com>

Closes #3145 from andrewor14/fix-make-distribution and squashes the following commits:

c78be61 [Andrew Or] Hot fix make distribution
[SPARK-3797] Minor addendum to Yarn shuffle service

I did not realize there was a `network.util.JavaUtils` when I wrote this code. This PR moves the `ByteBuffer` string conversion to the appropriate place. I tested the changes on a stable yarn cluster.

Author: Andrew Or <andrew@databricks.com>

Closes #3144 from andrewor14/yarn-shuffle-util and squashes the following commits:

b6c08bf [Andrew Or] Remove unused import
94e205c [Andrew Or] Use netty Unpooled
85202a5 [Andrew Or] Use guava Charsets
057135b [Andrew Or] Reword comment
adf186d [Andrew Or] Move byte buffer String conversion logic to JavaUtils
[SPARK-4277] Support external shuffle service on Standalone Worker

Author: Aaron Davidson <aaron@databricks.com>

Closes #3142 from aarondav/worker and squashes the following commits:

3780bd7 [Aaron Davidson] Address comments
2dcdfc1 [Aaron Davidson] Add private[worker]
47f49d3 [Aaron Davidson] NettyBlockTransferService shouldn't care about app ids (it's only b/t executors)
258417c [Aaron Davidson] [SPARK-4277] Support external shuffle service on executor
[SPARK-4188] [Core] Perform network-level retry of shuffle file fetches

This adds a RetryingBlockFetcher to the NettyBlockTransferService which is wrapped around our typical OneForOneBlockFetcher, adding retry logic in the event of an IOException.

This sort of retry allows us to avoid marking an entire executor as failed due to garbage collection or high network load.

TODO:
- [x] unit tests
- [x] put in ExternalShuffleClient too

Author: Aaron Davidson <aaron@databricks.com>

Closes #3101 from aarondav/retry and squashes the following commits:

72a2a32 [Aaron Davidson] Add that we should remove the condition around the retry thingy
c7fd107 [Aaron Davidson] Fix unit tests
e80e4c2 [Aaron Davidson] Address initial comments
6f594cd [Aaron Davidson] Fix unit test
05ff43c [Aaron Davidson] Add to external shuffle client and add unit test
66e5a24 [Aaron Davidson] [SPARK-4238] [Core] Perform network-level retry of shuffle file fetches
[SPARK-4236] Cleanup removed applications' files in shuffle service

This relies on a hook from whoever is hosting the shuffle service to invoke removeApplication() when the application is completed. Once invoked, we will clean up all the executors' shuffle directories we know about.

Author: Aaron Davidson <aaron@databricks.com>

Closes #3126 from aarondav/cleanup and squashes the following commits:

33a64a9 [Aaron Davidson] Missing brace
e6e428f [Aaron Davidson] Address comments
16a0d27 [Aaron Davidson] Cleanup
e4df3e7 [Aaron Davidson] [SPARK-4236] Cleanup removed applications' files in shuffle service
[SPARK-4204][Core][WebUI] Change Utils.exceptionString to contain the inner exceptions and make the error information in Web UI more friendly

This PR fixed `Utils.exceptionString` to output the full exception information. However, the stack trace may become very huge, so I also updated the Web UI to collapse the error information by default (display the first line and clicking `+detail` will display the full info).

Here are the screenshots:

Stages:
![stages](https://cloud.githubusercontent.com/assets/1000778/4882441/66d8cc68-6356-11e4-8346-6318677d9470.png)

Details for one stage:
![stage](https://cloud.githubusercontent.com/assets/1000778/4882513/1311043c-6357-11e4-8804-ca14240a9145.png)

The full information in the gray text field is:
```Java
org.apache.spark.shuffle.FetchFailedException: Connection reset by peer
	at org.apache.spark.shuffle.hash.BlockStoreShuffleFetcher$.org$apache$spark$shuffle$hash$BlockStoreShuffleFetcher$$unpackBlock$1(BlockStoreShuffleFetcher.scala:67)
	at org.apache.spark.shuffle.hash.BlockStoreShuffleFetcher$$anonfun$3.apply(BlockStoreShuffleFetcher.scala:83)
	at org.apache.spark.shuffle.hash.BlockStoreShuffleFetcher$$anonfun$3.apply(BlockStoreShuffleFetcher.scala:83)
	at scala.collection.Iterator$$anon$13.hasNext(Iterator.scala:371)
	at org.apache.spark.util.CompletionIterator.hasNext(CompletionIterator.scala:30)
	at org.apache.spark.InterruptibleIterator.hasNext(InterruptibleIterator.scala:39)
	at scala.collection.Iterator$$anon$11.hasNext(Iterator.scala:327)
	at scala.collection.Iterator$$anon$11.hasNext(Iterator.scala:327)
	at org.apache.spark.util.collection.ExternalAppendOnlyMap.insertAll(ExternalAppendOnlyMap.scala:129)
	at org.apache.spark.rdd.CoGroupedRDD$$anonfun$compute$5.apply(CoGroupedRDD.scala:160)
	at org.apache.spark.rdd.CoGroupedRDD$$anonfun$compute$5.apply(CoGroupedRDD.scala:159)
	at scala.collection.TraversableLike$WithFilter$$anonfun$foreach$1.apply(TraversableLike.scala:772)
	at scala.collection.mutable.ResizableArray$class.foreach(ResizableArray.scala:59)
	at scala.collection.mutable.ArrayBuffer.foreach(ArrayBuffer.scala:47)
	at scala.collection.TraversableLike$WithFilter.foreach(TraversableLike.scala:771)
	at org.apache.spark.rdd.CoGroupedRDD.compute(CoGroupedRDD.scala:159)
	at org.apache.spark.rdd.RDD.computeOrReadCheckpoint(RDD.scala:263)
	at org.apache.spark.rdd.RDD.iterator(RDD.scala:230)
	at org.apache.spark.rdd.MappedValuesRDD.compute(MappedValuesRDD.scala:31)
	at org.apache.spark.rdd.RDD.computeOrReadCheckpoint(RDD.scala:263)
	at org.apache.spark.rdd.RDD.iterator(RDD.scala:230)
	at org.apache.spark.rdd.FlatMappedValuesRDD.compute(FlatMappedValuesRDD.scala:31)
	at org.apache.spark.rdd.RDD.computeOrReadCheckpoint(RDD.scala:263)
	at org.apache.spark.rdd.RDD.iterator(RDD.scala:230)
	at org.apache.spark.scheduler.ResultTask.runTask(ResultTask.scala:61)
	at org.apache.spark.scheduler.Task.run(Task.scala:56)
	at org.apache.spark.executor.Executor$TaskRunner.run(Executor.scala:189)
	at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
	at java.lang.Thread.run(Thread.java:662)
Caused by: java.io.IOException: Connection reset by peer
	at sun.nio.ch.FileDispatcher.read0(Native Method)
	at sun.nio.ch.SocketDispatcher.read(SocketDispatcher.java:21)
	at sun.nio.ch.IOUtil.readIntoNativeBuffer(IOUtil.java:198)
	at sun.nio.ch.IOUtil.read(IOUtil.java:166)
	at sun.nio.ch.SocketChannelImpl.read(SocketChannelImpl.java:245)
	at io.netty.buffer.PooledUnsafeDirectByteBuf.setBytes(PooledUnsafeDirectByteBuf.java:311)
	at io.netty.buffer.AbstractByteBuf.writeBytes(AbstractByteBuf.java:881)
	at io.netty.channel.socket.nio.NioSocketChannel.doReadBytes(NioSocketChannel.java:225)
	at io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:119)
	at io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:511)
	at io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:468)
	at io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:382)
	at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:354)
	at io.netty.util.concurrent.SingleThreadEventExecutor$2.run(SingleThreadEventExecutor.java:116)
	... 1 more
```

/cc aarondav

Author: zsxwing <zsxwing@gmail.com>

Closes #3073 from zsxwing/SPARK-4204 and squashes the following commits:

176d1e3 [zsxwing] Add comments to explain the stack trace difference
ca509d3 [zsxwing] Add fullStackTrace to the constructor of ExceptionFailure
a07057b [zsxwing] Core style fix
dfb0032 [zsxwing] Backward compatibility for old history server
1e50f71 [zsxwing] Update as per review and increase the max height of the stack trace details
94f2566 [zsxwing] Change Utils.exceptionString to contain the inner exceptions and make the error information in Web UI more friendly
One more test with === conflicts.
Merge branch 'master' of https://github.com/apache/spark