CORD-523 Introduce generic routing service in Segment Routing

Segment Routing now reacts to routes being added/removed through RouteService.

SR will disable SingleSwitchFibInstaller if vRouter is activated

SR will install a routing table entry on
    - The leaf where next hop attaches to
    - The other leaves that points packets to the leaf where next hop attaches to

Host handler no longer add any IP flow for hosts outside the configured subnet
    - We need to explicitly add a per host route via RouteService when needed (vSG)

Change suppressSubnet behavior
    - Before: do not push any flow
    - After: ignore subnet config but still push filtering obj with VLAN 4094
             ARP handler drops all packets from suppressed ports

Additional refactoring
    - Remove vRouterId. Gateway router now needs to be specify through route API
    - Limit the scope of some variables
    - Unify handler.init method name

Change-Id: Idd2fd19fa74e3fa6209eef5cf2ed79957715c5e9
diff --git a/apps/routing/src/main/java/org/onosproject/routing/impl/SingleSwitchFibInstaller.java b/apps/routing/src/main/java/org/onosproject/routing/impl/SingleSwitchFibInstaller.java
index 66767a0..f0fe3fe 100644
--- a/apps/routing/src/main/java/org/onosproject/routing/impl/SingleSwitchFibInstaller.java
+++ b/apps/routing/src/main/java/org/onosproject/routing/impl/SingleSwitchFibInstaller.java
@@ -94,6 +94,8 @@
     private static final int PRIORITY_OFFSET = 100;
     private static final int PRIORITY_MULTIPLIER = 5;
 
+    // FIXME: This should be eliminated when we have an API in SR that
+    //        programs the fabric switches for VR
     public static final short ASSIGNED_VLAN = 4094;
 
     @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)