Restructure ProtoBuf & gRPC project structure

- pom.xml {protobuf, grpc}-dependencies to consolidte
  plugin configuration, dependency version property

- {protobuf, grpc}: ONOS App to load required feature/bundle

- all other atrifacts: Apps using protobuf/grpc inherit
  ~-dependencies above to reduce copy & paste configurations and
  dependency versions.

Change-Id: Ied90aff78ffddac6228d46e85e01d035eec37bee
diff --git a/incubator/protobuf-nb/pom.xml b/incubator/protobuf-nb/pom.xml
index 37a97bf..7802ef1 100644
--- a/incubator/protobuf-nb/pom.xml
+++ b/incubator/protobuf-nb/pom.xml
@@ -19,9 +19,10 @@
          xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
          xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <parent>
-        <artifactId>onos-incubator</artifactId>
+        <artifactId>onos-incubator-grpc-dependencies</artifactId>
         <groupId>org.onosproject</groupId>
         <version>1.9.0-SNAPSHOT</version>
+        <relativePath>../grpc-dependencies/pom.xml</relativePath>
     </parent>
     <modelVersion>4.0.0</modelVersion>
 
@@ -29,47 +30,27 @@
     <packaging>bundle</packaging>
 
     <properties>
-        <protobuf.version>3.0.0</protobuf.version>
-        <grpc.version>1.0.0</grpc.version>
     </properties>
 
     <dependencies>
         <dependency>
             <groupId>io.grpc</groupId>
             <artifactId>grpc-core</artifactId>
-            <version>${grpc.version}</version>
         </dependency>
+
         <dependency>
             <groupId>io.grpc</groupId>
             <artifactId>grpc-protobuf</artifactId>
-            <version>${grpc.version}</version>
         </dependency>
+
         <dependency>
             <groupId>io.grpc</groupId>
             <artifactId>grpc-stub</artifactId>
-            <version>${grpc.version}</version>
         </dependency>
+
     </dependencies>
 
     <build>
-        <extensions>
-            <extension>
-                <groupId>kr.motd.maven</groupId>
-                <artifactId>os-maven-plugin</artifactId>
-                <version>1.4.1.Final</version>
-            </extension>
-        </extensions>
-
-        <pluginManagement>
-            <plugins>
-                <plugin>
-                    <groupId>org.apache.karaf.tooling</groupId>
-                    <artifactId>karaf-maven-plugin</artifactId>
-                    <version>3.0.5</version>
-                    <extensions>true</extensions>
-                </plugin>
-            </plugins>
-        </pluginManagement>
 
         <plugins>
             <!-- TODO This is included to suppress the generation of javadocs for
@@ -87,44 +68,11 @@
             <plugin>
                 <groupId>org.xolstice.maven.plugins</groupId>
                 <artifactId>protobuf-maven-plugin</artifactId>
-                <version>0.5.0</version>
-                <configuration>
-                    <!-- The version of protoc must match protobuf-java. If you don't
-                        depend on protobuf-java directly, you will be transitively depending on the
-                        protobuf-java version that grpc depends on. -->
-                    <protocArtifact>com.google.protobuf:protoc:${protobuf.version}:exe:${os.detected.classifier}</protocArtifact>
-                    <pluginId>grpc-java</pluginId>
-                    <pluginArtifact>io.grpc:protoc-gen-grpc-java:${grpc.version}:exe:${os.detected.classifier}</pluginArtifact>
-                </configuration>
-                <executions>
-                    <execution>
-                        <goals>
-                            <goal>compile</goal>
-                            <goal>compile-custom</goal>
-                        </goals>
-                    </execution>
-                </executions>
             </plugin>
 
             <plugin>
                 <groupId>org.codehaus.mojo</groupId>
                 <artifactId>build-helper-maven-plugin</artifactId>
-                <version>1.11</version>
-                <executions>
-                    <execution>
-                        <id>add-source</id>
-                        <phase>generate-sources</phase>
-                        <goals>
-                            <goal>add-source</goal>
-                        </goals>
-                        <configuration>
-                            <sources>
-                                <source>${project.build.directory}/generated-sources/protobuf/java</source>
-                                <source>${project.build.directory}/generated-sources/protobuf/grpc-java</source>
-                            </sources>
-                        </configuration>
-                    </execution>
-                </executions>
             </plugin>
         </plugins>
     </build>