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
Merge remote-tracking branch 'apache/branch-0.9' into branch-0.9