Small fixes to the main "index" view for alerts. Move the
manage_password page for LV-EM observers to the ligoauth app and
show a link to it from the navbar to those users.

* Filter available contacts for a notification to be verified
  contacts belonging to the user
* New better code for handling label queries
* Some better help text for notification forms
* Remove old notification forms and views

New model functionality, better forms and views.

Separate phone and email contacts, add verification of contact
information, improve views and forms.

Also squash migrations in the alerts app.

Some of the search utilities were still in the separate
events and superevents apps, so we moved them to the search app
and tried to clean things up a bit.  It's still kind of a mess
and probably not worth doing a full cleanup until we rework
the search.

Removing old alert code in alerts.old_alert.  Finished migration
to new code by updating the phone stuff.

Instantiating a new alerts app and moving the alert functionality from
events/alert.py to alerts/old_alert.py. This commit forms a starting
point where the old alert functionality is still in place and we can
rework the alert infrastructure to be more modularized, flexible,
and adapted to superevents.

A loophole allowed LVC users who are also LV-EM members to access
the page for creating/managing passwords for basic auth access
to the API.  This commit fixes that by also checking for the
absence of LVC membership before allowing access to the page.

updating flash messaging for contact/notification creation to use django message middleware rather than session

Localize EMFootprint start times to UTC.
Changed event creation time query to assume UTC.

and email notifications. This is done by parsing
the label query separately and applying the filter
in a separate step.