Author: witgo <witgo@qq.com>

Closes #969 from witgo/yarn_ClientBase and squashes the following commits:

8117765 [witgo] review commit
3bdbc52 [witgo] Merge branch 'master' of https://github.com/apache/spark into yarn_ClientBase
5261b6c [witgo] fix sys.props.get("SPARK_YARN_DIST_FILES")
e3c1107 [witgo] update docs
b6a9aa1 [witgo] merge master
c8b4554 [witgo] review commit
2f48789 [witgo] Merge branch 'master' of https://github.com/apache/spark into yarn_ClientBase
8d7b82f [witgo] Merge branch 'master' of https://github.com/apache/spark into yarn_ClientBase
1048549 [witgo] remove Utils.resolveURIs
871f1db [witgo] add spark.yarn.dist.* documentation
41bce59 [witgo] review commit
35d6fa0 [witgo] move to ClientArguments
55d72fc [witgo] Merge branch 'master' of https://github.com/apache/spark into yarn_ClientBase
9cdff16 [witgo] review commit
8bc2f4b [witgo] review commit
20e667c [witgo] Merge branch 'master' into yarn_ClientBase
0961151 [witgo] merge master
ce609fc [witgo] Merge branch 'master' into yarn_ClientBase
8362489 [witgo] yarn.ClientBase spark.yarn.dist.* do not work