Changes to vsgTest to query dhcp vcpes by querying the test config.
Add support and functions to locate vsg for a vcpe.
And send remote vcpe commands. (wan/lan port up for the vcpe)
Care has to be taken to reach the vcpes considering that after the dhcp ip is obtained on the vcpe,
the compute nodes would become inaccessible through the fabric.
Hence the test wrapper running commands on vcpe through compute node tries to open up the management port for the test.

Change-Id: I987bea9c92d3866c82151f21fd3ba16283585887
diff --git a/src/test/utils/OltConfig.py b/src/test/utils/OltConfig.py
index 571ce7e..cd52ff5 100644
--- a/src/test/utils/OltConfig.py
+++ b/src/test/utils/OltConfig.py
@@ -136,3 +136,6 @@
             if self.olt_conf.has_key('vcpe'):
                 return self.olt_conf['vcpe']
         return []
+
+    def get_vcpes_by_type(self, service):
+        return filter(lambda vcpe: vcpe['type'].lower() == service.lower(), self.get_vcpes())