Models which inherit from AutoIncrementModel can now specify
more than one constraint.  Needed for superevent categories.

Link to correct file versions in superevent log comments

Fixing issue where users could cause superevent date ID lookup
to fail by providing date strings which couldn't be parsed by
datetime.datetime.strptime (ex: '181309', month=13). Now we raise
a custom exception in the class method and catch it in
get_superevent_by_date_id_or_404.

Replacing redundant logic for superevent queries to just use
Superevent.get_filter_kwargs_for_date_id_lookup so as to "NRY".

Fixing ambiguity in superevent date IDs due to use of a 2 digit year.
datetime uses some range like 1969-2068, but we would prefer something
more GPS-centric, so we force it to be 1980-2079.

This will need to be dealt with in advance of 2080, probably
will need to convert to 4 digit years.  Shouldn't be too hard,
will likely need to just make the switch, but maintain legacy
compatibility with legacy URLs, search features, and a check in
Superevent.get_filter_kwargs_for_date_id_lookup, which
points to superevents between 1980-2079 if a 2 digit year is given.

A few divs were inside of the wrong {% endif %} block in the coinc
inspiral templates.  Caused display issues if for some reason the
event did not have any single inspiral events.

Adding serialized label object to label creation and removal
alerts.  This may not be permanent, but some users want this
feature since the object contains a 'self' link which
they use to tell alerts from different servers apart.

Adding DQOK, PASTRO_READY, EMBRIGHT_READY, SKYMAP_READY,
GCN_PRELIM_SENT labels in advance of first OPA test.

Applying SafeCreateMixin to the superevent viewset.  This way,
model-level validation errors will be caught and handled
appropriately.

Adding file url to serialized superevent logs. This matches the
format for event logs and is necessary to display images properly
in the nasty javascript for the web view.

A list of superevents which need operator signoff will appear
on the home page if the user signs in from an IFO control room.

Adding some optimization in search forms by using select_related
and prefetch_related.  Some of this is on the Superevent model
within the get_internal_events and get_external_events methods.

Show group, pipeline, search by default for event searches,
hide link to files.

New /latest/ page includes events and superevents. We also
move the old events 'latest' page to /events/latest/, changed the
view name, and fixed reverses to that page appropriately.

Adding view functions, templates, and full nasty javascript
to get a more complete and (hopefully) temporary implementation
of the superevent detail view ready. This includes buttons for
allowing/removing LV-EM access and forms for signoffs.

Using new create_versioned_file utility in create_log functions,
adding ability to provide queryset to get_superevent_by_date_id_or_404,
changing a few comments for autogenerated log messages

Added some utilities for handling signoffs for superevents,
including alerts, labels, logs, etc.

Small update to methods which build VOEvent files for events
to match superevents and play nicely with changes to
gracedb-client.

Adding API resource for creating and getting VOEvents from superevents.

New CommaSeparatedOrListField type which accepts a comma-separated
string (and splits it into a list) or a list input.  Useful for
handling input from the web interface as well as from the Python
client in either form.

Changing \d+ to \d{6} in superevent date ID regex.  This prevents
ValueErrors from occurring when people try to go to URLs like
/superevents/view/S0001.

Adding ability to create_emobservation to handle comma-separated
strings as input rather than lists, which is necessary for handling
input from the web form on the event pages.

Updating create_emobservation to work for new
gracedb-client method of uploading emobservation
parameters.

Adding EMObservation creation and alerts for superevents.
Note that this required a change to gracedb-client.

Allow EMObservation fields ra, dec, raWidth, and decWidth to be
blank in forms, resulting in a null database entry.