Failover to lvalert_send now uses new LVALert Python API, rather
than forking a Process to call the lvalert_send script.

Upgrade to newest LVAlert package and fix some requirements.
There is a bug with sleekxmpp and certain versions of pyasn1-modules,
so we revert the version of that and pyasn1. We also remove some
requirements which are really dependencies of requirements.

The 'search' and 'latest' pages will now default to superevents
rather than events.

All calls to event.graceid() -> event.graceid.

Improve log messages for signoff creation. Bugfix for handling
whether alerts are issued for "sub-functions" or not. Some
minor organizational changes.

Enforce label protection through the API for applying labels,
removing labels, and creating events and superevents with labels
attached.  We also don't allow users to reapply a signoff request
label when a signoff status label is already applied (e.g., can't
apply ADVREQ when ADVNO already exists).

Add a boolean column called 'protected' to the Label model.
Protected labels will not be allowed to be directly applied, but
will be applied as a part of another process (like signoffs).
We also create a data migration which sets some existing labels
as protected (ADV(OK|NO), (H1|L1|V1)(OK|NO))

'EM_Superseded ' -> 'EM_Superseded'. This has been fixed manually on
all servers.  Note that it wasn't a problem on the production
server because that migration was "reworked" within the last year
and was not actually applied in production (it was 'faked').

New mixin for doing some kind of validation on the request data
or the instance before destroying it.

Want to see what is triggering this functionality, if it is
being triggered at all.

Fixing a bug in superevent queries by creation time:
using Combine on the expression resulted in incorrect args
being passed to construct a datetime object.

* Consolidated *all* of the search stuff into the search app
  (previously the flexigrid stuff was in events/superevents)
* Completely removed the old events-only search and latest views,
  templates, etc.
* Removed some old unit tests which tested the events-only search

Prevent the function for generating search results for the flexigrid
table from being accessed except by AJAX. This prevents users from
overriding the expected parameters and generating server errors.

Instruments should be read from the coinc_inspiral table,
not the coinc_event table.  Fix this for all CBC pipelines and
for Omega, too.

Remove handling for .gwf event files for MBTA submissions.
Comments indicate that this was deprecated in 2014 and could be
removed in 2015.

Add ordering for nested views for a superevent: events, voevents,
and EMObservations.

Create generalized methods for nested viewsets. There is now a
default get_queryset method which finds the nested model queryset
through the parent object; the user can specify filtering parameters
as well.  We also added a order_by filter for list views; parameters
can be specified on the class.

Use text input for event graceid in web browsable API form for
adding an event to a superevent.

silk was slowing things quite a bit so we won't use it by default,
even in development instances.

The serializers for logs and emobservations (for both events and
superevents) now give the user's full name for web views (unless
it's blank; then fallback to username) and the username otherwise.
We check for web view 'status' by seeing whether it is an AJAX
request. This matches the previous behavior before the development
of the superevents features.

Rename config/settings/test.py -> config/settings/dev.py to prevent
the file from being picked up by the test runner during unit testing.

Use DelimitedOrListField for tag names and tag display names
in the web API form for superevent log creation.

CommaSeparatedOrListField is now called DelimitedOrListField.
Default delimiter is ',', but the user can specify anything.
Some improvements to not show [] in web forms by default and
properly handle empty inputs.

Changing superevents serializer to use text input fields for
'preferred_event' and 'events'.  The 'events' field also will now
accept a comma-separated list.  This prevents timeout errors when
trying to render all the options for events in the form and speeds
up page load times significantly for this view.

Fixed case where external user creates a log message with no
tags so that add_tag permission is not incorrectly required.