Replace inheritance hierarchy with composition

In the process of unification of the clients code we should use
composition to allow easier replacement with common HTTPClient.

Related to blueprint common-client-library-2

Change-Id: I5addc38eb2e2dd0be91b566fda7c0d81787ffa75

glanceclient/v1/client.py

@@ -18,7 +18,7 @@ from glanceclient.v1 import images
 from glanceclient.v1 import image_members
 
 
-class Client(http.HTTPClient):
+class Client(object):
     """Client for the OpenStack Images v1 API.
 
     :param string endpoint: A user-supplied endpoint URL for the glance
@@ -30,6 +30,6 @@ class Client(http.HTTPClient):
 
     def __init__(self, *args, **kwargs):
         """Initialize a new client for the Images v1 API."""
-        super(Client, self).__init__(*args, **kwargs)
-        self.images = images.ImageManager(self)
-        self.image_members = image_members.ImageMemberManager(self)
+        self.http_client = http.HTTPClient(*args, **kwargs)
+        self.images = images.ImageManager(self.http_client)
+        self.image_members = image_members.ImageMemberManager(self.http_client)

glanceclient/v1/legacy_shell.py

@@ -75,7 +75,7 @@ def print_image_formatted(client, image):
     :param client: The Glance client object
     :param image: The image metadata
     """
-    uri_parts = urlparse.urlparse(client.endpoint)
+    uri_parts = urlparse.urlparse(client.http_client.endpoint)
     if uri_parts.port:
         hostbase = "%s:%s" % (uri_parts.hostname, uri_parts.port)
     else:

tests/v1/test_legacy_shell.py

@@ -27,7 +27,9 @@ class LegacyShellV1Test(testtools.TestCase):
     def test_print_image_formatted(self):
 
         class FakeClient():
-            endpoint = 'http://is.invalid'
+            class FakeHTTPClient():
+                endpoint = 'http://is.invalid'
+            http_client = FakeHTTPClient()
 
         class FakeImage():
             id = 1