Make the replica transformer kind aware.

The previous implementation had a bug and poorly handled
types that should not have a `spec: replica:` field.

Documentation is updated to reflect the change in behavior,
and better highlights the cases where a patch should be
used instead of this shorthand.

pkg/transformers/config/defaultconfig/replicas.go

@@ -0,0 +1,20 @@
+package defaultconfig
+
+const replicasFieldSpecs = `
+replicas:
+- path: spec/replicas
+  create: true
+  kind: Deployment
+
+- path: spec/replicas
+  create: true
+  kind: ReplicationController
+
+- path: spec/replicas
+  create: true
+  kind: ReplicaSet
+
+- path: spec/replicas
+  create: true
+  kind: StatefulSet
+`