Add pkg/fall for Fallthrough (#1355)

* Add pkg/fall for Fallthrough

Move this into it's own package to facilitate tests. Important bug
was fixed: make the names fully qualified.

Add fall package to hosts, reverse, etcd, and fix kubernetes and any
tests. The k8s tests are still as-is, might need a future cleanup.

plugin/kubernetes/setup_test.go

@@ -347,7 +347,7 @@ func TestKubernetesParse(t *testing.T) {
 			defaultResyncPeriod,
 			"",
 			podModeDisabled,
-			&[]string{"ip6.arpa", "inaddr.arpa", "foo.com"},
+			&[]string{"ip6.arpa.", "inaddr.arpa.", "foo.com."},
 			nil,
 		},
 		// Valid upstream
@@ -443,7 +443,7 @@ func TestKubernetesParse(t *testing.T) {
 		}
 
 		// fallthrough
-		foundFallthrough := k8sController.Fallthrough
+		foundFallthrough := k8sController.Fall
 		if foundFallthrough != nil {
 			failed := false
 			if test.expectedFallthrough == nil {