This commit consists of:
1) Update the voltha.proto to remove duplicates between the voltha message and
the CoreInstance.   Since all data will be stored into the clustered KV store
then it makes sense to use a clustered proto message instead of core specific.
Each core will hold a subset of the data, only those it is actively or passively
managing.
2) Add a Makefile into the adapters directory to clearly separate the build of
adapters to the core build.   This is work in progress.
3) Add an initial readme.md into the adapters directory to show how to run ponsim
olt and onu adapters in containers
4) Minor cleanup, mostly around name consistency.

Change-Id: I55155c41b56e95877f8735b536873a87d6ca63b1
diff --git a/protos/voltha.proto b/protos/voltha.proto
index 92d59dd..6d37329 100644
--- a/protos/voltha.proto
+++ b/protos/voltha.proto
@@ -75,25 +75,15 @@
     string package_name = 2;
 }
 
-// Top-level (root) node for a Voltha Instance
+// CoreInstance represents a core instance.  It is data held in memory when a core
+// is running.  This data is not persistent.
 message CoreInstance {
     option (yang_message_rule) = CREATE_BOTH_GROUPING_AND_CONTAINER;
 
     string instance_id = 1  [(access) = READ_ONLY];
 
-    string version = 2 [(access) = READ_ONLY];
+    HealthStatus health = 2 [(child_node) = {}];
 
-    LogLevel.LogLevel log_level = 3;
-
-    HealthStatus health = 10 [(child_node) = {}];
-
-    repeated LogicalDevice logical_devices = 12 [(child_node) = {key: "id"}];
-
-    repeated Device devices = 13 [(child_node) = {key: "id"}];
-
-    repeated DeviceGroup device_groups = 15 [(child_node) = {key: "id"}];
-
-    repeated AlarmFilter alarm_filters = 16 [(child_node) = {key: "id"}];
 }
 
 message CoreInstances {
@@ -101,25 +91,23 @@
     repeated string items = 1;
 }
 
-// Voltha representing the entire Voltha cluster
+// Voltha represents the Voltha cluster data.  Each Core instance will hold a subset of
+// the entire cluster. However, some items (e.g. adapters) will be held by all cores
+// for better performance
 message Voltha {
     option (yang_message_rule) = CREATE_BOTH_GROUPING_AND_CONTAINER;
 
     string version = 1 [(access) = READ_ONLY];
 
-    LogLevel.LogLevel log_level = 2;
+    repeated Adapter adapters = 2 [(child_node) = {key: "id"}];
 
-    repeated CoreInstance core_instances = 3 [(child_node) = {key: "instance_id"}];
+    repeated LogicalDevice logical_devices = 3 [(child_node) = {key: "id"}];
 
-    repeated Adapter adapters = 11 [(child_node) = {key: "id"}];
+    repeated Device devices = 4 [(child_node) = {key: "id"}];
 
-    repeated LogicalDevice logical_devices = 12 [(child_node) = {key: "id"}];
+    repeated DeviceGroup device_groups = 5 [(child_node) = {key: "id"}];
 
-    repeated Device devices = 13 [(child_node) = {key: "id"}];
-
-    repeated DeviceGroup device_groups = 15 [(child_node) = {key: "id"}];
-
-    repeated AlarmFilter alarm_filters = 16 [(child_node) = {key: "id"}];
+    repeated AlarmFilter alarm_filters = 6 [(child_node) = {key: "id"}];
 
     repeated
         omci.MibDeviceData omci_mib_database = 28