Adding some base-classes to eliminate event and listener boiler-plate code throughout a number of subsystems.

Refactored all core components to take advantage of this; apps remain to be done.

Change-Id: Ib0935ba07ff81b0fa032534004ec9ac6187cbf22
diff --git a/core/pom.xml b/core/pom.xml
index 84dca6e..0f7dd8c 100644
--- a/core/pom.xml
+++ b/core/pom.xml
@@ -57,6 +57,10 @@
             <groupId>org.osgi</groupId>
             <artifactId>org.osgi.compendium</artifactId>
         </dependency>
+        <dependency>
+            <groupId>org.apache.felix</groupId>
+            <artifactId>org.apache.felix.scr.annotations</artifactId>
+        </dependency>
     </dependencies>
 
     <build>
@@ -70,6 +74,11 @@
                 <groupId>org.onosproject</groupId>
                 <artifactId>onos-maven-plugin</artifactId>
             </plugin>
+
+            <plugin>
+                <groupId>org.apache.felix</groupId>
+                <artifactId>maven-scr-plugin</artifactId>
+            </plugin>
         </plugins>
     </build>