All middleware equal (#535)

* all-middleware-equal

* Revert "all-middleware-equal"

This reverts commit ee77b2a981.

* middleware: treat external and local the same

Make the middleware generation simpler and also specify the local
middleware, meaning that it can now be removed as well. Simplify
the code a bit and regen everything.

* remove lineNR, not used

core/dnsserver/zdirectives.go

@@ -30,7 +30,6 @@ var directives = []string{
 	"kubernetes",
 	"reverse",
 	"proxy",
-	"httpprox",
 	"whoami",
 	"erratic",
 }