[EV-63] Add the ability to log timing information to local logs for c…

Correctly use the Logger.exception method to capture exception backtraces if datadog timing logging fails

Only initialize formatters once, so that datadog is only initialized once, no matter how many plays are run

# The first commit's message is:

Pass playbook_timestamp into Formatters directly, rather than pulling it from callback_module

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#	fixup! Pass playbook_timestamp into Formatters directly, rather than pulling it from callback_module

Change nginx old listen parameter from default to default_server

Fix stupid bug on master from 6fc28e55

OPS-1536: Add python3 support to xqwatcher

Add support for initial password hash feature to user management playbook.

Prevously, supervisor was starting during AMI builds (and other times
when disable_edx_services was true). This is unnecessary, since none of
the services will be linked into supervisor anyways.

Previously, xqwatcher put supervisor in its own app dir for historical
reasons. This change brings xqwatcher in line with how the rest of our
IDAs use supervisor.

Right now the PPA is only serving newer versions of python2 than Ubuntu
PPAs are providing for trusty and precise. Since the version provided
for xenial is new enough, there's no reason to use a custom PPA, and
this saves us from having to support more unnecessary Ubuntu releases in
our PPA.

Specify a socket timeout for pymongo and lower the connect timeout.