Editorial updates to common files, including sentence-style headings and consistency/clarity edits

Partial-Bug: #1250515

backport: havana

Change-Id: I9675dffd130c8aa6343143d9806adb4e0b74a55d
author: diane fleming

doc/common/section_dashboard_sessions.xml

@@ -14,7 +14,7 @@
             /etc/openstack-dashboard/local_settings</filename>, on Ubuntu and Debian:
             <filename>/etc/openstack-dashboard/local_settings.py</filename> and on openSUSE: <filename
         >/usr/share/openstack-dashboard/openstack_dashboard/local/local_settings.py</filename>).
-    </para>
+   </para>
     <para>The following sections describe the pros and cons of each
         option as it pertains to deploying the dashboard.</para>
     <section xml:id="dashboard-session-local">
@@ -48,7 +48,7 @@ CACHES = {
         <para>You can use applications such as Memcached or Redis for external
             caching. These applications offer persistence and shared storage
             and are useful for small-scale deployments and/or development.
-        </para>
+       </para>
         <section xml:id="dashboard-session-memcached">
         <title>Memcached</title>
         <para>Memcached is an high-performance and distributed memory object caching system
@@ -96,7 +96,7 @@ CACHES = {
         </section>
     </section>
     <section xml:id="dashboard-session-database">
-        <title>Database</title>
+        <title>Initialize and configure the database</title>
         <para>Database-backed sessions are scalable, persistent, and
             can be made high-concurrency and highly-available.</para>
         <para>However, database-backed sessions are one of the slower
@@ -105,7 +105,6 @@ CACHES = {
             can also be a substantial undertaking and is far beyond
             the scope of this documentation.</para>
         <procedure>
-            <title>To initialize and configure the database:</title>
             <step>
                 <para>Start the mysql command line client:</para>
                 <screen><prompt>$</prompt> <userinput>mysql -u root -p</userinput></screen>
@@ -173,14 +172,14 @@ No fixtures found.</computeroutput></screen>
                     symbolic link settings:</para>
                     <para>On Ubuntu:
                     <screen><prompt>#</prompt> <userinput>/etc/init.d/apache2 restart</userinput></screen>
-                    </para>
+                   </para>
                     <para>On Fedora/RHEL/CentOS:
                 <screen><prompt>#</prompt> <userinput>service httpd restart</userinput></screen>
                 <screen><prompt>#</prompt> <userinput>service apache2 restart</userinput></screen>
-                    </para>
+                   </para>
                     <para>On openSUSE:
                 <screen><prompt>#</prompt> <userinput>systemctl restart apache2.service</userinput></screen>
-                    </para>
+                   </para>
             </step>
             <step>
                 <para>On Ubuntu, restart the <systemitem class="service">nova-api</systemitem> service to ensure that the