Add release notes and an error message for release

In prepping for 1.14.0, it seemed there were a couple of important
release notes missing, as well as an informative error message
in case someone installs shade fresh and then tries to use
glance_client.

Change-Id: I17b8e7d3d1f6ac8172e49f4473137f51351f7e5d

releasenotes/notes/fixed-magnum-type-7406f0a60525f858.yaml

@@ -0,0 +1,6 @@
+---
+fixes:
+  - Fixed magnum service_type. shade was using it as 'container'
+    but the correct type is 'container-infra'. It's possible that on
+    old clouds with magnum shade may now do the wrong thing. If that
+    occurs, please file a bug.

releasenotes/notes/removed-glanceclient-105c7fba9481b9be.yaml

@@ -0,0 +1,9 @@
+---
+prelude: >
+    This release marks the beginning of the path towards removing all
+    of the 'python-*client' libraries as dependencies. Subsequent releases
+    should expect to have fewer and fewer library depdencies.
+upgrade:
+  - Removed glanceclient as a dependency. All glance operations
+    are now performed with direct REST calls using keystoneauth
+    Adapter.

shade/openstackcloud.py

@@ -993,7 +993,17 @@ class OpenStackCloud(_normalize.Normalizer):
 
     @property
     def glance_client(self):
-        import glanceclient
+        warnings.warn(
+            'Using shade to get a glance_client object is deprecated. If you'
+            ' need a raw glanceclient.Client object, please use'
+            ' make_legacy_client in os-client-config instead')
+        try:
+            import glanceclient
+        except ImportError:
+            self.log.error(
+                'glanceclient is no longer a dependency of shade. You need to'
+                ' install python-glanceclient directly.')
+            raise
         if self._glance_client is None:
             self._glance_client = self._get_client(
                 'image', glanceclient.Client)