Bundle tachyon:  SPARK-1269

This should all work as expected with the current version of the tachyon tarball (0.4.1)

Author: Nick Lanham <nick@afternight.org>

Closes #137 from nicklan/bundle-tachyon and squashes the following commits:

2eee15b [Nick Lanham] Put back in exec, start tachyon first
738ba23 [Nick Lanham] Move tachyon out of sbin
f2f9bc6 [Nick Lanham] More checks for tachyon script
111e8e1 [Nick Lanham] Only try tachyon operations if tachyon script exists
0561574 [Nick Lanham] Copy over web resources so web interface can run
4dc9809 [Nick Lanham] Update to tachyon 0.4.1
0a1a20c [Nick Lanham] Add scripts using tachyon tarball
(cherry picked from commit a18ea00f3af0fa4c6b2c59933e22b6c9f0f636c8)

Signed-off-by: Patrick Wendell <pwendell@gmail.com>
[SPARK-1274] Add dev scripts to merge PRs and create releases from master to branch-0.9

All the files are one-to-one copied from master. Only the Spark version numbers were changed.

Author: Tathagata Das <tathagata.das1565@gmail.com>

Closes #176 from tdas/branch-0.9 and squashes the following commits:

fb1b913 [Tathagata Das] Changed version numbers for 0.9.1 release.
3303d5e [Tathagata Das] Copied Apache release scripts in master to branch-0.9
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>