Add the DNS message response flags as {rflags} to the default logging
Also complete the replacer testing that is was commented out.
And (unrelated) Switch erratic and whoami to ease testing.
Note: {flags} could and should be added as well - but we can leave that
as a beginners bug.
Move all (almost all) Go files in middleware into their
own packages. This makes for better naming and discoverability.
Lot of changes elsewhere to make this change.
The middleware.State was renamed to request.Request which is better,
but still does not cover all use-cases. It was also moved out middleware
because it is used by `dnsserver` as well.
A pkg/dnsutil packages was added for shared, handy, dns util functions.
All normalize functions are now put in normalize.go
