remove stacked views

[smnorris]

Materialized view definitions can't be simply altered to add/remove a column of interest, the whole view must be dropped/recreated.
Lots of additional views hang off of crossings_vw - adding a single column as in #559 requires a massive chain of dropping/recreating of dependent fptwg reporting views.

There must be a cleaner way to manage this?

[smnorris]

A materialized view for crossings_vw is fine - and useful.
Updating the fptwg views to pull from the source tables is probably the best fix. Stacked views = bad