deprecate some stuff (#1732)

https_google and reverse will be removed in 2 releases. Add warnings.

We will move reverse to coredns/reverse and list it as external after
this switch.

See #1713

plugin/reverse/setup.go

@@ -10,10 +10,13 @@ import (
 	"github.com/coredns/coredns/core/dnsserver"
 	"github.com/coredns/coredns/plugin"
 	"github.com/coredns/coredns/plugin/pkg/fall"
+	clog "github.com/coredns/coredns/plugin/pkg/log"
 
 	"github.com/mholt/caddy"
 )
 
+var log = clog.NewWithPlugin("reverse")
+
 func init() {
 	caddy.RegisterPlugin("reverse", caddy.Plugin{
 		ServerType: "dns",
@@ -31,6 +34,9 @@ func setup(c *caddy.Controller) error {
 		return Reverse{Next: next, Networks: networks, Fall: fall}
 	})
 
+	// TODO(miek): Deprecate after 1.1.3 (that would be 1.2.0)
+	log.Warning("reverse will be deprecated in the next release")
+
 	return nil
 }