Fix nits from commit that introduces cursive

Change I80fcafa528b87a83b90ed7c0e4c0db9228852bc2 has some nits that need
not be fixed right away. This commit fixes them based on the comments:

  * use of named arguments in glance/location.py to avoid regression
    caused by inadvertant change to add, remove or update those
    arguments in the library
  * release notes file name prefix is change to something that's more
    discoverable rather than a simple bug name which doesn't give any
    clue if you are browsing through glance code
  * release notes use wrapping at 60 so that's fixed
  * updated a link in the release notes that's a official repository
    link to the project
  * updated release note to remove the prelude section as per
    discussion on https://review.openstack.org/#/c/364586 , PS 3.
  * different formatting style in release note as per reno docs

Change-Id: I08a32215d2ff40299919f859f8d18f5400641311

glance/location.py

@@ -421,8 +421,9 @@ class ImageProxy(glance.domain.proxy.Image):
             key_type = extra_props[signature_utils.KEY_TYPE]
             cert_uuid = extra_props[signature_utils.CERT_UUID]
             verifier = signature_utils.get_verifier(
-                self.context, cert_uuid, hash_method,
-                img_signature, key_type
+                context=self.context, cert_uuid=cert_uuid,
+                hash_method=hash_method, img_signature=img_signature,
+                key_type=key_type
             )
         else:
             verifier = None

releasenotes/notes/bug-1528349-c6b15d94845232da.yaml

@@ -1,16 +0,0 @@
----
-prelude: >
-    Glance and Nova contain nearly identical digital signature modules. In
-    order to better maintain and evolve this code and to eliminate
-    the possibility that the modules diverge, we propose removing this code
-    and instead using the new cursive library. Please read the other section
-    for more details.
-other:
-  - The cursive library is an OpenStack project which implements
-    OpenStack-specific verification of digital signatures. In Newton, the
-    majority of the signature verification code was removed from Glance.
-    Cursive has been added to Glance as a dependency and will be installed by
-    default. Glance uses the Cursive library's functionality to verify digital
-    signatures. To familiarize yourself with this new dependency and see the
-    list of transitive dependencies visit
-    https://github.com/openstack/cursive

releasenotes/notes/use-cursive-c6b15d94845232da.yaml

@@ -0,0 +1,22 @@
+---
+other:
+  - |
+    Glance and Nova contain nearly identical digital
+    signature modules. In order to better maintain and
+    evolve this code and to eliminate the possibility that
+    the modules diverge, we have replaced the digital
+    signature module in Glance with the new ``cursive``
+    library.
+
+    * The ``cursive`` library is an OpenStack project which
+      implements OpenStack-specific verification of digital
+      signatures.
+    * In Newton, the majority of the signature verification
+      code was removed from Glance. ``cursive`` has been
+      added to Glance as a dependency and will be installed
+      by default.
+    * Glance uses the ``cursive`` library's functionality to
+      verify digital signatures. To familiarize yourself
+      with this new dependency and see the list of
+      transitive dependencies visit
+      http://git.openstack.org/cgit/openstack/cursive