bugfix: Wrong "Duration" in "Active Stages" in stages page

If a stage which has completed once loss parts of data, it will be resubmitted. At this time, it appears that stage.completionTime > stage.submissionTime.

Author: shiyun.wxm <shiyun.wxm@taobao.com>

Closes #170 from BlackNiuza/duration_problem and squashes the following commits:

a86d261 [shiyun.wxm] tow space indent
c0d7b24 [shiyun.wxm] change the style
3b072e1 [shiyun.wxm] fix scala style
f20701e [shiyun.wxm] bugfix: "Duration" in "Active Stages" in stages page

(cherry picked from commit d55ec86de2e96f7dc9d1dd107daa35c3823791ec)
Signed-off-by: Reynold Xin <rxin@apache.org>
SPARK-1203 fix saving to hdfs from yarn

Author: Thomas Graves <tgraves@apache.org>

Closes #173 from tgravescs/SPARK-1203 and squashes the following commits:

4fd5ded [Thomas Graves] adding import
964e3f7 [Thomas Graves] SPARK-1203 fix saving to hdfs from yarn
Update the yarn alpha version to 0.9.1-incubating-SNAPSHOT
Merge remote-tracking branch 'apache-github/branch-0.9' into branch-0.9-fix