[SPARK-1930] The Container is running beyond physical memory limits, so as to be killed

Author: witgo <witgo@qq.com>

Closes #894 from witgo/SPARK-1930 and squashes the following commits:

564307e [witgo] Update the running-on-yarn.md
3747515 [witgo] Merge branch 'master' of https://github.com/apache/spark into SPARK-1930
172647b [witgo] add memoryOverhead docs
a0ff545 [witgo] leaving only two configs
a17bda2 [witgo] Merge branch 'master' of https://github.com/apache/spark into SPARK-1930
478ca15 [witgo] Merge branch 'master' into SPARK-1930
d1244a1 [witgo] Merge branch 'master' into SPARK-1930
8b967ae [witgo] Merge branch 'master' into SPARK-1930
655a820 [witgo] review commit
71859a7 [witgo] Merge branch 'master' of https://github.com/apache/spark into SPARK-1930
e3c531d [witgo] review commit
e16f190 [witgo] different memoryOverhead
ffa7569 [witgo] review commit
5c9581f [witgo] Merge branch 'master' into SPARK-1930
9a6bcf2 [witgo] review commit
8fae45a [witgo] fix NullPointerException
e0dcc16 [witgo] Adding  configuration items
b6a989c [witgo] Fix container memory beyond limit, were killed