[SPARK-2635] Fix race condition at SchedulerBackend.isReady in standalone mode

In SPARK-1946(PR #900), configuration <code>spark.scheduler.minRegisteredExecutorsRatio</code> was introduced. However, in standalone mode, there is a race condition where isReady() can return true because totalExpectedExecutors has not been correctly set.

Because expected executors is uncertain in standalone mode, the PR try to use CPU cores(<code>--total-executor-cores</code>) as expected resources to judge whether SchedulerBackend is ready.

Author: li-zhihui <zhihui.li@intel.com>
Author: Li Zhihui <zhihui.li@intel.com>

Closes #1525 from li-zhihui/fixre4s and squashes the following commits:

e9a630b [Li Zhihui] Rename variable totalExecutors and clean codes
abf4860 [Li Zhihui] Push down variable totalExpectedResources to children classes
ca54bd9 [li-zhihui] Format log with String interpolation
88c7dc6 [li-zhihui] Few codes and docs refactor
41cf47e [li-zhihui] Fix race condition at SchedulerBackend.isReady in standalone mode
[SPARK-2861] Fix Doc comment of histogram method

Tested and ready to merge.

Author: Chandan Kumar <chandan.kumar@imaginea.com>

Closes #1786 from nrchandan/spark-2861 and squashes the following commits:

cb0bc1e [Chandan Kumar] [SPARK-2861] Fix a typo in the histogram doc comment
6a2a71b [Chandan Kumar] SPARK-2861. Fix Doc comment of histogram method
[SPARK-1766] sorted functions to meet pedantic requirements

Pedantry is underrated

Author: Chris Cope <ccope@resilientscience.com>

Closes #1859 from copester/master and squashes the following commits:

0fb4499 [Chris Cope] [SPARK-1766] sorted functions to meet pedantic requirements
[SPARK-2894] spark-shell doesn't accept flags

As sryza reported, spark-shell doesn't accept any flags.
The root cause is wrong usage of spark-submit in spark-shell and it come to the surface by #1801

Author: Kousuke Saruta <sarutak@oss.nttdata.co.jp>
Author: Cheng Lian <lian.cs.zju@gmail.com>

Closes #1715, Closes #1864, and Closes #1861

Closes #1825 from sarutak/SPARK-2894 and squashes the following commits:

47f3510 [Kousuke Saruta] Merge branch 'master' of git://git.apache.org/spark into SPARK-2894
2c899ed [Kousuke Saruta] Removed useless code from java_gateway.py
98287ed [Kousuke Saruta] Removed useless code from java_gateway.py
513ad2e [Kousuke Saruta] Modified util.sh to enable to use option including white spaces
28a374e [Kousuke Saruta] Modified java_gateway.py to recognize arguments
5afc584 [Cheng Lian] Filter out spark-submit options when starting Python gateway
e630d19 [Cheng Lian] Fixing pyspark and spark-shell CLI options
Updated Spark SQL README to include the hive-thriftserver module

Author: Reynold Xin <rxin@apache.org>

Closes #1867 from rxin/sql-readme and squashes the following commits:

42a5307 [Reynold Xin] Updated Spark SQL README to include the hive-thriftserver module
Turn UpdateBlockInfo into case class.

This helps us log UpdateBlockInfo properly once #1870 is merged.

Author: Reynold Xin <rxin@apache.org>

Closes #1872 from rxin/UpdateBlockInfo and squashes the following commits:

0cee1c2 [Reynold Xin] Turn UpdateBlockInfo into case class.
Remove extra semicolon in Task.scala

Author: GuoQiang Li <witgo@qq.com>

Closes #1876 from witgo/remove_semicolon_in_Task_scala and squashes the following commits:

c6ea732 [GuoQiang Li] Remove extra semicolon in Task.scala
[SPARK-2950] Add gc time and shuffle write time to JobLogger

The JobLogger is very useful for performing offline performance profiling of Spark jobs. GC Time and Shuffle Write time are available in TaskMetrics but are currently missed from the JobLogger output. This patch adds these two fields.

~~Since this is a small change, I didn't create a JIRA. Let me know if I should do that.~~

cc kayousterhout

Author: Shivaram Venkataraman <shivaram@cs.berkeley.edu>

Closes #1869 from shivaram/job-logger and squashes the following commits:

1b709fc [Shivaram Venkataraman] Add a space before GC_TIME
c418105 [Shivaram Venkataraman] Add gc time and shuffle write time to JobLogger
[SPARK-2898] [PySpark] fix bugs in deamon.py

1. do not use signal handler for SIGCHILD, it's easy to cause deadlock
2. handle EINTR during accept()
3. pass errno into JVM
4. handle EAGAIN during fork()

Now, it can pass 50k tasks tests in 180 seconds.

Author: Davies Liu <davies.liu@gmail.com>

Closes #1842 from davies/qa and squashes the following commits:

f0ea451 [Davies Liu] fix lint
03a2e8c [Davies Liu] cleanup dead children every seconds
32cb829 [Davies Liu] fix lint
0cd0817 [Davies Liu] fix bugs in deamon.py
Merge branch 'master' of https://git-wip-us.apache.org/repos/asf/spark into netty-conf-with-sort