handle changes to writeLog client function and clean up display name handling for tagging of event logs

changing format for event EMObservations and EMFootprint creation timestamps when these objects are converted to dicts

Adding custom pagination to superevents API to match events. It's bad, but will have to serve until we can redo the whole thing

updating event tag and event log tag resources to include more information than just a link to the detail page

adding superevent API urls - currently nesting them within the events API; should eventually be moved to a separate API app

generalizing and abstracting several models in the events app, as well as fixing many field parameters

Need to make sure values are actually numeric types before
just passing them to isnan(), since it can't handle them, apparently.

Adding some requirements to migrations to enforce proper ordering.

Renaming LIB -> oLIB and gstlal-spiir -> spiir, at the request of
the pipelines.

gstlal wants to set eff_distance to nan when they don't have a
meaningful value for it.  Unfortunately, we can't save that in the
database because MySQL numeric types can't deal with nans. So we
check for nans in this field and set it to NULL if it is nan,
before saving it in the database.

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.

Updated from Django 1.11.5 to Django 1.11.14. Updated 3rd party
packages so that all of them have version requirements in
requirements.txt.  Also updated most of these packages to use the
newest versions.  A specific update to the twilio package required
some changes for how we determine the 'from' phone number. Also
alphabetized the packages in this file.  Finally, added the very
useful django-silk debugger/profiler.