Prevents server errors from being generated when the filename is
"bad" and when the user specifies a non-integer version. This is
for superevent files; event files are handled separately, although
this should be unified at some point.

We use get_or_create now to add labels to a superevent in order
to prevent IntegrityErrors when a user makes the same request
too rapidly and both sneak by the initial check.

overseer seems to always exit with an exit code of 0, which means
that 'autorestart=unexpected' does not restart it. So we set it
to 'true' instead.

Not feasible to use multiple DBs for read or write operations at
present. We're going to have to revisit this at some point. We leave
most of the code in place but commented out.

Add capability for passing kwargs to AlertIssuer classes'
issue_alerts() method.  We take advantage of this in the update
alerts for checking for FAR changes and NSCAND state changes.

Add a whole suite of tests for phone and email alerts. Small update
to a few unit tests for alert views.

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.