(cherry picked from commit bb5bc41f)

removing unneeded, missing alternatives

bad diag

missed var

(cherry picked from commit 0ca865c9)

Make changes for running analyticstack on 16.04.

* Replace llvm-gcc with gcc.
* Define new Hadoop services.
* Add retry when first using Hadoop.
* Update procps package to address bug.
* Increase memory from 4GB to 6GB.
* Disable vmem-check in yarn.

(cherry picked from commit 1c138599)

Since the earliest days of edX, we've run gunicorn with preload_app as
True. This was primarily because the first handful of courses were using
the XMLModuleStore, which was extremely slow to initialize because it
had to read entire courses from disk and load them into memory at
startup.

XMLModuleStore courses stopped being created with the introduction of
Studio, and we've long since removed them from edx.org. Note: This
should not be confused with importing courses that are authored in XML.
XMLModuleStore courses are courses who use the disk instead of Mongo
for content persistence, and require a server restart for content edits
to show.

This commit sets things back to how Django is more commonly deployed
with gunicorn. It will make server startup time somewhat more expensive
because each worker process does init work, but it should make it
easier to safely enable features like database connection pooling
without having to worry about shared resources.

[PERF-305]

(cherry picked from commit 30b924d5)

(cherry picked from commit e90ed376)

(cherry picked from commit ff65c883)

Cherry pick ebb13031

update firefox version test for jenkins workers

(cherry picked from commit 37dfceb6)

(cherry picked from commit d891e660)

temp add stop-automatic-updates to packer scripts

(cherry-picked from 304d6ead)

We already do this in the common role but not in bootstrap or abbey roles.

(cherry picked from commit b78c0487)

See https://github.com/ansible/ansible/issues/21316

This prevented successful installation of open-release/ficus.1rc

(cherry picked from commit a79fe1b7)

Apply the change to install MySQL 5.6 from an edX PPA

(cherry picked from commit 6218350b)

(cherry picked from commit b8ed4f49)

(cherry picked from commit 6e4a47de)

Cherry pick from c6514cca

Use my-passwords.yml in sandbox.sh

(cherry picked from commit f3970b73af316502722e6153f11af52f7b61112d)
(cherry picked from commit 81cc046ff09e69642eeb7cb82aa1f7b08b28c649)

(cherry picked from commit b2beddb4d35c12537d17454e543363201c578cd8)

Cherry-picked from 5 commits, from PR's #3654 and #3670:

(cherry picked from commit 3df8af7f)

(cherry picked from commit 8cad356a)

(cherry picked from commit 2ef0aa42)

(cherry picked from commit 59b50c82)

(cherry picked from commit 00be986f)

(cherry picked from commit a3975c4e)

This should help decrease build times.

ECOM-6600

Cherry pick from 64facf1b

Cherry picked from e4cacb16