Moved the javascript for this button to a new location in the main
JS file and added button enable/disable code to prevent "too fast"
or multiple clicks.

The 'confirm GW' button on the superevent web detail page now
uses AJAX to make the request to the corresponding API endpoint.
As a result, the separate view function for this endpoint in the
superevents app is no longer needed, so we have deleted it.

ModelToDict mixin was supposed to be a generic way of serializing
models, but we decided to go with the serializers from rest_framework
for generic serialization throughout the proejct.

Removing old web views for superevents app which are no longer
used and cleaning up imports.

Since we use direct foreign keys for superevent permission tracking,
there is no need to delete GropuObjectPermissions when we do a
"purge" delete.

Adding unit test setup classes for managing signoffs and related
permissions.  Also updated permissions assigned to groups
in this test setup.

Updating and adding utility functions for exposing/hiding
superevents and managing signoffs.

Changing signoff form and expose/hide button on the superevent
web display to make an AJAX request to the relevant API endpoints.
This way, we don't have to maintain separate permissions and views
for web resources.

Added properties to superevents which alias other attributes:
  * gpstime = t_0
  * graceid = superevent_id

Adding an endpoint to the superevents API for listing, retrieving,
and modifying superevent access permissions.  Includes views,
a serializer, permissions, urls, etc.

Adding permissions for viewing GOPs attached to a superevent and
the is_exposed field, which will track whether a superevent is
exposed to the public or not.

Adding signoff viewset, serializer, permissions, urls, unit tests,
etc. to the superevents API.

Changed key for response data from 'signoff' to 'signoffs' in
the events API. Historically, there has not been a client method
for accessing this endpoint, so there should not be any issues
with compatibility.

Moving indicator for a test server (config_name) from just below
the navbar to the main heading.

Instantiating a second version for the API.  For now, it's identical
to v1, but can be customized as needed in the future.

Added filtering to recently-updated web-based search for events
and superevents, based on view permissions.

Fixed two bugs in web-based event log creation: first, attempts
to save an EventLog with a null filename, and attempted creation
of the 'lvem' tag with the wrong information, possibly resulting in
an IntegrityError due to duplicate tags.

Deleting unit tests for SupereventForm form, which no longer exists.

Moving a few base class throttles and fields from the events app up
one level so that they can be used elsewhere.

Many of the classes (permissions, mixins, etc.) in the superevents
API follow a general pattern of
    1. Abstract customized version of a DRF class
    2. Class-specific, customized version of #1
    3. (optional) Implemented, class-specific version of #2
We want all classes in #1 to either be in the root api directory
or the root versioned (api.v*) directory.  #2 and #3 classes should
be in api.v*.superevents. This commit just moves some of the classes
in #1 and #2 around so that they can eventually be used in the events
API.

Moved events.api and superevents.api into the new api app.
We want to have a versioned API, so these are now in
api.v1.events and api.v1.superevents, respectively. Part of this
change is that we require a custom reverse function (api_reverse)
for handling versioning. Much of the required code changes for this
migration include converting reverses to use this function and
changing relative imports appropriately.