Several fixes to SRMulticast
- Add host discovery and location verifications
- Flush arp entries before host discovery
- Update mcast join and delete commands

Change-Id: If5c6d85e7441010c63ebf45f333552e24a07352c
diff --git a/TestON/drivers/common/cli/emulator/mininetclidriver.py b/TestON/drivers/common/cli/emulator/mininetclidriver.py
index 59e1441..c5ee51d 100644
--- a/TestON/drivers/common/cli/emulator/mininetclidriver.py
+++ b/TestON/drivers/common/cli/emulator/mininetclidriver.py
@@ -605,6 +605,8 @@
                     main.log.warn( "No IP addresses configured on host {}, skipping discovery".format( host ) )
                     discoveryResult = main.FALSE
                 if cmd:
+                    self.handle.sendline( "{} ip neigh flush all".format( host ) )
+                    self.handle.expect( "mininet>", timeout=wait + 1 )
                     self.handle.sendline( cmd )
                     self.handle.expect( "mininet>", timeout=wait + 1 )
             return discoveryResult