SPARK-4971: Fix typo in BlockGenerator comment

Author: CodingCat <zhunansjtu@gmail.com>

Closes #3807 from CodingCat/new_branch and squashes the following commits:

5167f01 [CodingCat] fix typo in the comment
MAINTENANCE: Automated closing of pull requests.

This commit exists to close the following pull requests on Github:

Closes #3456 (close requested by 'pwendell')
Closes #1602 (close requested by 'tdas')
Closes #2633 (close requested by 'tdas')
Closes #2059 (close requested by 'JoshRosen')
Closes #2348 (close requested by 'tdas')
Closes #3662 (close requested by 'tdas')
Closes #2031 (close requested by 'andrewor14')
Closes #265 (close requested by 'JoshRosen')
[SPARK-3787][BUILD] Assembly jar name is wrong when we build with sbt omitting -Dhadoop.version

This PR is another solution for When we build with sbt with profile for hadoop and without property for hadoop version like:

    sbt/sbt -Phadoop-2.2 assembly

jar name is always used default version (1.0.4).

When we build with maven with same condition for sbt, default version for each profile is used.
For instance, if we  build like:

    mvn -Phadoop-2.2 package

jar name is used hadoop2.2.0 as a default version of hadoop-2.2.

Author: Kousuke Saruta <sarutak@oss.nttdata.co.jp>

Closes #3046 from sarutak/fix-assembly-jarname-2 and squashes the following commits:

41ef90e [Kousuke Saruta] Merge branch 'master' of git://git.apache.org/spark into fix-assembly-jarname-2
50c8676 [Kousuke Saruta] Merge branch 'fix-assembly-jarname-2' of github.com:sarutak/spark into fix-assembly-jarname-2
52a1cd2 [Kousuke Saruta] Fixed comflicts
dd30768 [Kousuke Saruta] Merge branch 'master' of git://git.apache.org/spark into fix-assembly-jarname2
f1c90bb [Kousuke Saruta] Fixed SparkBuild.scala in order to read `hadoop.version` property from pom.xml
af6b100 [Kousuke Saruta] Merge branch 'master' of git://git.apache.org/spark into fix-assembly-jarname
c81806b [Kousuke Saruta] Merge branch 'master' of git://git.apache.org/spark into fix-assembly-jarname
ad1f96e [Kousuke Saruta] Merge branch 'master' of git://git.apache.org/spark into fix-assembly-jarname
b2318eb [Kousuke Saruta] Merge branch 'master' of git://git.apache.org/spark into fix-assembly-jarname
5fc1259 [Kousuke Saruta] Fixed typo.
eebbb7d [Kousuke Saruta] Fixed wrong jar name
HOTFIX: Slight tweak on previous commit.

Meant to merge this in when committing SPARK-3787.
[SPARK-3955] Different versions between jackson-mapper-asl and jackson-c...

...ore-asl

- set the same version to jackson-mapper-asl and jackson-core-asl
- It's related with #2818
- coded a same patch from a latest master

Author: Jongyoul Lee <jongyoul@gmail.com>

Closes #3716 from jongyoul/SPARK-3955 and squashes the following commits:

efa29aa [Jongyoul Lee] [SPARK-3955] Different versions between jackson-mapper-asl and jackson-core-asl - set the same version to jackson-mapper-asl and jackson-core-asl
[SPARK-4954][Core] add spark version infomation in log for standalone mode

The master and worker spark version may be not the same with Driver spark version. That is because spark Jar file might be replaced for new application without restarting the spark cluster. So there shall log out the spark-version in both Mater and Worker log.

Author: Zhang, Liye <liye.zhang@intel.com>

Closes #3790 from liyezhang556520/version4Standalone and squashes the following commits:

e05e1e3 [Zhang, Liye] add spark version infomation in log for standalone mode
[SPARK-4952][Core]Handle ConcurrentModificationExceptions in SparkEnv.environmentDetails

Author: GuoQiang Li <witgo@qq.com>

Closes #3788 from witgo/SPARK-4952 and squashes the following commits:

d903529 [GuoQiang Li] Handle ConcurrentModificationExceptions in SparkEnv.environmentDetails
Fault tolerance for RpcEndpoint
Merge branch 'master' into rpc