Fix broken links

Contributor guide:

* Replace absolute link with in-tree relative one that
  should always work.
* The task detail patch contained a template, not a link. Change text
  accordingly.

Change-Id: Id72c7fba272090c5f439980ad58db48db42faa16
Releasenotes: REmove link to document that does not exist anymore.

doc/contributor-guide/source/release/taskdetail.rst

@@ -60,7 +60,7 @@ Speciality Team lead, listed at :doc:`../team-structure`., and ask them for
 the notes for the books they look after. The source repository for release
 notes is `openstack-manuals/releasenotes/source/RELEASENAME` and they are
 published to
-<http://docs.openstack.org/releasenotes/openstack-manuals/RELEASENAME.html>.
+``http://docs.openstack.org/releasenotes/openstack-manuals/RELEASENAME.html``.
 
 Publish index page
 ~~~~~~~~~~~~~~~~~~

doc/contributor-guide/source/ux-ui-guidelines/gui-guidelines.rst

@@ -157,8 +157,7 @@ the ``X`` on the upper right corner of the message.
 
    The error message height should vary to fit the content.
 
-For more information on guidelines for UI text, see:
-`<http://docs.openstack.org/contributor-guide/ui-text-guidelines.html>`_.
+For more information on guidelines for UI text, see :ref:`uitextguidelines`.
 
 Actions
 -------

releasenotes/source/mitaka.rst

@@ -20,8 +20,7 @@ High Availability Guide
   installation and configuration details.
 
 * Documented the `Pacemaker cluster manager <http://docs.openstack.org/ha-guide/intro-ha-arch-pacemaker.html>`_
-  and `Keepalived architecture <http://docs.openstack.org/ha-guide/intro-ha-arch-keepalived.html>`_
-  details and limitations.
+  and Keepalived architecture details and limitations.
 
 * Added the `MariaDB Galera cluster <http://docs.openstack.org/ha-guide/shared-database.html>`_
   installation, configuration, and management details.