HTTP requests were only returning the error message to the caller, not
logging locally. In most cases the problem could be understood
client-side, but there are some exceptions. E.g. if Moonfire returns
a 403 on WebSocket update, even in the Chrome debug tools's network
tab the HTTP response body seems to be unavailable. And in general,
it's nice to have more context server-side.
Logging a `response::Body` isn't practical (it could be a stream), so
convert all the web stuff to use `base::Error` err returns.
Convert the `METHOD_NOT_ALLOWED` paths to return `Ok` for now. This is a
bit lame but punts on having some way of plumbing an explicit/overridden
status code in `base::Error`, as no gRPC error kind cleanly maps to
that.
Also convert `db::auth`, rather than making up an error kind in the web
layer.
This is also a small step toward getting rid of `failure::Error`.
In particular, the docs now talk about the CSRF protection. This is
increasing relevant as we start having more mutation endpoints. And
make the signals api expect a csrf for session auth to match the newer
users api.
This is useful for e.g. deciding whether or not to present the user
admin UI in navigation.
As part of this change, I adjusted the casing in Permissions, and then
all the toml stuff for consistency. Noted in changelog.
I mistakenly left this out. Also, fix the behavior if something is
forgotten. Before, it'd silently ignore it. Now, it correctly returns
Unimplemented, in both POST /api/users/:id and PUT /api/users.
