Convert all service clients to global CONF object

This commit takes the rest client and all subclass(all the service
clients) and converts all uses of config to the global CONF object.

Partially implements bp config-cleanup

Change-Id: I09525af4f1b308b91d45b7bbea05e0f734ea485c
diff --git a/tempest/services/identity/v3/xml/endpoints_client.py b/tempest/services/identity/v3/xml/endpoints_client.py
index bd23674..e1df3a9 100644
--- a/tempest/services/identity/v3/xml/endpoints_client.py
+++ b/tempest/services/identity/v3/xml/endpoints_client.py
@@ -18,19 +18,22 @@
 
 from tempest.common import http
 from tempest.common.rest_client import RestClientXML
+from tempest import config
 from tempest.services.compute.xml.common import Document
 from tempest.services.compute.xml.common import Element
 from tempest.services.compute.xml.common import xml_to_json
 
+CONF = config.CONF
+
 XMLNS = "http://docs.openstack.org/identity/api/v3"
 
 
 class EndPointClientXML(RestClientXML):
 
-    def __init__(self, config, username, password, auth_url, tenant_name=None):
-        super(EndPointClientXML, self).__init__(config, username, password,
+    def __init__(self, username, password, auth_url, tenant_name=None):
+        super(EndPointClientXML, self).__init__(username, password,
                                                 auth_url, tenant_name)
-        self.service = self.config.identity.catalog_type
+        self.service = CONF.identity.catalog_type
         self.endpoint_url = 'adminURL'
 
     def _parse_array(self, node):
@@ -47,7 +50,7 @@
 
     def request(self, method, url, headers=None, body=None, wait=None):
         """Overriding the existing HTTP request in super class RestClient."""
-        dscv = self.config.identity.disable_ssl_certificate_validation
+        dscv = CONF.identity.disable_ssl_certificate_validation
         self.http_obj = http.ClosingHttp(
             disable_ssl_certificate_validation=dscv)
         self._set_auth()