Added OpenVswitch support (OVS)

Added gbics to inventory.
Added ability to change chassis, blade, and server roles
Added Generic Host type - this can be used for any server.
Added tag support for the host.
Added sudo support - agent can run as a non-root user, and use root
      only for the collection programs.

Bugfix - running -u (update) on a blade server failed

netbox_agent/vendors/generic.py

@@ -0,0 +1,23 @@
+import netbox_agent.dmidecode as dmidecode
+from netbox_agent.server import ServerBase
+
+
+class GenericHost(ServerBase):
+    def __init__(self, *args, **kwargs):
+        super(GenericHost, self).__init__(*args, **kwargs)
+        self.manufacturer = dmidecode.get_by_type('Baseboard')[0].get('Manufacturer')
+
+    def is_blade(self):
+        return None
+
+    def get_blade_slot(self):
+        return None
+
+    def get_chassis_name(self):
+        return None
+
+    def get_chassis(self):
+        return self.get_product_name()
+
+    def get_chassis_service_tag(self):
+        return self.get_service_tag()