Cleanup docs and the chaos middleware

Make the CH middleware actually work. Needs a bit of a hack to route

the fake version.bind and friends zone to the correct handler. Fiddle

with the order in directive.go so that CH queries get logged as well.



Secondly add class rewriting to the rewrite middleware handler and also

log the class by default.

middleware/etcd/handler.go

@@ -1,6 +1,7 @@
 package etcd
 
 import (
+	"fmt"
 	"strings"
 
 	"github.com/miekg/coredns/middleware"
@@ -11,6 +12,9 @@ import (
 
 func (e Etcd) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) (int, error) {
 	state := middleware.State{W: w, Req: r}
+	if state.QClass() != dns.ClassINET {
+		return dns.RcodeServerFailure, fmt.Errorf("etcd: can only deal with ClassINET")
+	}
 
 	// We need to check stubzones first, because we may get a request for a zone we
 	// are not auth. for *but* do have a stubzone forward for. If we do the stubzone