log.js: fix inconsistency on page refresh

 - Change the filter to "errors only"
 - Hit refresh
 -> Filter will remain on "errors only"; the actual filtering should
    reflect that.

We forgot to check the "initial" state of the select box after installing
the event handler.  Fix that.

I'm not bothering to fix the flash-of-unbehavioured-content right now.
I think that's a fairly obvious temporary glitch compared to the
head-scratching inconsistency here.
core_modules/ doesn't exist anymore (#740/#741)

It's now bonfire/modules
builder: fix submit after form validation failure
Respect values of auth.password_min_length below 8 (issue #749)

No comment on how valid a choice it is.  Still, password strength is
supposed to be centralised in valid_password().  And if Bonfire wants to
restrict the allowed setting, we need to say so on the settings page.
Not silently ignore the user setting :).
Fix PHP error when re-activating user (issue #714)

I haven't tested sending the activation email though.