Moved BGP code and Router code into their own bundle.

The main goal of this is to allow routing code to be used by multiple
applications.

Changes include:
 * Created an onos-app-routing bundle and moved BGP code and routing code
   into it.
 * Created an onos-app-routing-api bundle as a common API bundle between
   onos-app-routing and onos-app-sdnip, to prevent circular dependencies.
 * Moved API classes into onos-app-routing-api bundle.
 * Made Router and BgpSessionManager into OSGi components. This is not quite
   clean, because there is still a chain of start() method calls from SdnIp
   through to BgpSessionManager to preserve startup order. This should be
   revisted so components can be started using activate()
 * Created BgpService and RoutingService APIs to glue different components
   together.
 * Many unit test changes. A lot of the previous unit tests spanned the
   Router and IntentSynchronizer classes, but this is not possible any more
   since these classes are in different bundles. I had to rewrite some of
   these tests so that each unit test class only tests one real class. A
   nice side-effect is that the tests are now simpler because each test
   tests less functionality.
 * Removed SdnIp test seeing as it doesn't run automatically, was already
   broken and has been largely superseded by other unit tests and the nightly
   functional tests.

Change-Id: I70ecf5391aa353e99e7cdcf7ed38a530c87571bb
diff --git a/apps/pom.xml b/apps/pom.xml
index ca64e5f..2746e65 100644
--- a/apps/pom.xml
+++ b/apps/pom.xml
@@ -46,6 +46,8 @@
         <module>oecfg</module>
         <module>demo</module>
         <module>election</module>
+        <module>routing</module>
+        <module>routing-api</module>
     </modules>
 
     <properties>