Report moderation

    - redaction marked with [...]
    - of report and comments
    - stores original data
    - uses a single form, on the report/_main view
    - requires additional permissions (user_body_permissions)
    - Hide report functionality
    - Moderation notification/contact form
    - Moderation writes to admin_log
Tests for moderation
Move bromley from report hiding to moderation

The feature to hide reports is still enabled, as it is used by other
`users_can_hide` bodies.  As we want to roll out moderation to Bromley,
in this commit we hide the functionality *only* for Bromley.  Of course
if we migrate those other users to this moderation method, then we will
need to make equivalent change to general template, and remove the
functionality from Report.pm.
refactor repeat code into get_email_template
Moderation - update-schema fixed and improved

    bin/update-schema --commit should now work

A downgrade is also provided.  Run bin/update-schema --help for details
use site_title in password titles (for makemyisland), part of #863
add partnership not (Fonadhoo Council), part of #863
replace FixMyStreet with site_title in contact blurb
use loc() strings and site_title in faq/privacy/contact 'static' page nav (#863)

Note I think there's a case for escalating these changes into the core templates,
but I don't know if site_title has been used consistently enough for this to
be safe and it seems like a tricky thing to test?
use MakeMyIsland literal instead of site_title
force alerts to a single hardcoded feed for Fonadhoo
add MakeMyIsland language domain (so "FixMyStreet" -> "MakeMyIsland")

So bin/make_po is needed to generate locale/MakeMyIsland.po in situ.
add MakeMyIsland sig, etc., to emails