This commit consists of:
1) Dockerizing the netconf server
2) Update proto2yang to support module imports
3) Provide a set of yang modules derived from the proto files in voltha.
   These files as well as the slight mmodifications to the proto files are
   provided in the experiments/netconf/proto2yang directory
4) Code to automatically pull proto files from voltha into the netconf server,
   compiles them and produce the yang equivalent files.
5) Add a getvoltha netconf API to provide voltha state information (basic at
   this time).  There is potential to make this generic once we experiment
   with additional APIs

Change-Id: I94f3a1f871b8025ad675d5f9b9b626d1be8b8d36
diff --git a/experiments/netconf/proto2yang/meta.proto b/experiments/netconf/proto2yang/meta.proto
new file mode 100644
index 0000000..d16668a
--- /dev/null
+++ b/experiments/netconf/proto2yang/meta.proto
@@ -0,0 +1,46 @@
+// Copyright (c) 2015, Google Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// This file contains annotation definitions that can be used to describe
+// a configuration tree.
+
+syntax = "proto3";
+
+package voltha;
+
+import "google/protobuf/descriptor.proto";
+
+message ChildNode {
+    string key = 1;
+}
+
+enum Access {
+    CONFIG = 0;  // read-write, stored
+    READ_ONLY = 1;      // read-only field
+}
+
+extend google.protobuf.FieldOptions {
+
+    // If present, it indicates that this field is stored as external child node
+    // or children nodes in Voltha's internal configuration tree.
+    // If the field is a container field and if the option specifies a key
+    // the child objects will be addressible by that key.
+    ChildNode child_node = 7761772;
+
+    // This annotation can be used to indicate that a field is read-only,
+    // from the perspective of NBI access. Backend plugins and system
+    // internals can update the field but the update requests through the
+    // NBI will ignore for instance a field that is marked as read-only (RO).
+    Access access = 7761773;
+}