[SPARK-2298] Encode stage attempt in SparkListener & UI.

Simple way to reproduce this in the UI:

```scala
val f = new java.io.File("/tmp/test")
f.delete()
sc.parallelize(1 to 2, 2).map(x => (x,x )).repartition(3).mapPartitionsWithContext { case (context, iter) =>
  if (context.partitionId == 0) {
    val f = new java.io.File("/tmp/test")
    if (!f.exists) {
      f.mkdir()
      System.exit(0);
    }
  }
  iter
}.count()
```

Author: Reynold Xin <rxin@apache.org>

Closes #1545 from rxin/stage-attempt and squashes the following commits:

3ee1d2a [Reynold Xin] - Rename attempt to retry in UI. - Properly report stage failure in FetchFailed.
40a6bd5 [Reynold Xin] Updated test suites.
c414c36 [Reynold Xin] Fixed the hanging in JobCancellationSuite.
b3e2eed [Reynold Xin] Oops previous code didn't compile.
0f36075 [Reynold Xin] Mark unknown stage attempt with id -1 and drop that in JobProgressListener.
6c08b07 [Reynold Xin] Addressed code review feedback.
4e5faa2 [Reynold Xin] [SPARK-2298] Encode stage attempt in SparkListener & UI.
[SPARK-2967][SQL] Fix sort based shuffle for spark sql.

Add explicit row copies when sort based shuffle is on.

Author: Michael Armbrust <michael@databricks.com>

Closes #2066 from marmbrus/sortShuffle and squashes the following commits:

fcd7bb2 [Michael Armbrust] Fix sort based shuffle for spark sql.
SPARK_LOGFILE and SPARK_ROOT_LOGGER no longer need in spark-daemon.sh

Author: wangfei <wangfei_hello@126.com>

Closes #2057 from scwf/patch-7 and squashes the following commits:

1b7b9a5 [wangfei] SPARK_LOGFILE and SPARK_ROOT_LOGGER no longer need in spark-daemon.sh