Detangling incubator: virtual nets, tunnels, resource labels, oh my

- virtual networking moved to /apps/virtual; with CLI & REST API
- tunnels and labels moved to /apps/tunnel; with CLI & REST API; UI disabled for now
- protobuf/models moved to /core/protobuf/models
- defunct grpc/rpc registry stuff left under /graveyard
- compile dependencies on /incubator moved to respective modules for compilation
- run-time dependencies will need to be re-tested for dependent apps

- /graveyard will be removed in not-too-distant future

Change-Id: I0a0b995c635487edcf95a352f50dd162186b0b39
diff --git a/apps/virtual/BUILD b/apps/virtual/BUILD
new file mode 100644
index 0000000..1f3cb57
--- /dev/null
+++ b/apps/virtual/BUILD
@@ -0,0 +1,13 @@
+BUNDLES = [
+    "//apps/virtual/api:onos-apps-virtual-api",
+    "//apps/virtual/app:onos-apps-virtual-app",
+]
+
+onos_app(
+    app_name = "org.onosproject.virtual",
+    category = "Traffic Engineering",
+    description = "Virtual Network Subsystem extension",
+    included_bundles = BUNDLES,
+    title = "Virtual Network Subsystem",
+    url = "http://onosproject.org",
+)