Update OpenHashSet.scala

Modify wrong comment of function addWithoutResize.

Author: ArcherShao <ArcherShao@users.noreply.github.com>

Closes #667 from ArcherShao/patch-3 and squashes the following commits:

a607358 [ArcherShao] Update OpenHashSet.scala
SPARK-1474: Spark on yarn assembly doesn't include AmIpFilter

We use org.apache.hadoop.yarn.server.webproxy.amfilter.AmIpFilter in spark on yarn but are not included it in the assembly jar.

I tested this on yarn cluster by removing the yarn jars from the classpath and spark runs fine now.

Author: Thomas Graves <tgraves@apache.org>

Closes #406 from tgravescs/SPARK-1474 and squashes the following commits:

1548bf9 [Thomas Graves] SPARK-1474: Spark on yarn assembly doesn't include org.apache.hadoop.yarn.server.webproxy.amfilter.AmIpFilter
Fix two download suggestions in the docs:

1) On the quick start page provide a direct link to the downloads (suggested by @pbailis).
2) On the index page, don't suggest users always have to build Spark, since many won't.

Author: Patrick Wendell <pwendell@gmail.com>

Closes #662 from pwendell/quick-start and squashes the following commits:

0622f27 [Patrick Wendell] Fix two download suggestions in the docs:
[SPARK-1685] Cancel retryTimer on restart of Worker or AppClient

See https://issues.apache.org/jira/browse/SPARK-1685 for a more complete description, but in essence: If the Worker or AppClient actor restarts before successfully registering with Master, multiple retryTimers will be running, which will lead to less than the full number of registration retries being attempted before the new actor is forced to give up.

Author: Mark Hamstra <markhamstra@gmail.com>

Closes #602 from markhamstra/SPARK-1685 and squashes the following commits:

11cc088 [Mark Hamstra] retryTimer -> registrationRetryTimer
69c348c [Mark Hamstra] Cancel retryTimer on restart of Worker or AppClient
Merge branch 'master' of github.com:apache/spark into pyspark-exception