Improve installation instructions with pg_ctl in documentation

The documentation includes sections to be able to initialize and start
Postgres via a couple of commands.  Some of its recommendations involve
using directly "postgres", which is inconsistent with the recommendation
given by initdb.  At the same time make some other command calls more
consistent with the rest, by using an absolute path when creating a
database.

Author: Andreas Scherbaum
Reviewed-by: Michael Banck, Ryan Lambert

doc/src/sgml/installation.sgml

@@ -37,7 +37,7 @@ mkdir /usr/local/pgsql/data
 chown postgres /usr/local/pgsql/data
 su - postgres
 /usr/local/pgsql/bin/initdb -D /usr/local/pgsql/data
-/usr/local/pgsql/bin/postgres -D /usr/local/pgsql/data >logfile 2>&1 &
+/usr/local/pgsql/bin/pg_ctl -D /usr/local/pgsql/data -l logfile start
 /usr/local/pgsql/bin/createdb test
 /usr/local/pgsql/bin/psql test
 </synopsis>

doc/src/sgml/standalone-install.xml

@@ -77,25 +77,21 @@ postgres$ <userinput>/usr/local/pgsql/bin/initdb -D /usr/local/pgsql/data</useri
      The previous <command>initdb</command> step should have told you how to
      start up the database server. Do so now. The command should look
      something like:
-<programlisting>/usr/local/pgsql/bin/postgres -D /usr/local/pgsql/data</programlisting>
-     This will start the server in the foreground. To put the server
-     in the background use something like:
-<programlisting>nohup /usr/local/pgsql/bin/postgres -D /usr/local/pgsql/data \
-    &lt;/dev/null &gt;&gt;server.log 2&gt;&amp;1 &lt;/dev/null &amp;</programlisting>
+<programlisting>/usr/local/pgsql/bin/pg_ctl -D /usr/local/pgsql/data start</programlisting>
     </para>
 
     <para>
      To stop a server running in the background you can type:
-<programlisting>kill `cat /usr/local/pgsql/data/postmaster.pid`</programlisting>
+<programlisting>/usr/local/pgsql/bin/pg_ctl -D /usr/local/pgsql/data stop</programlisting>
     </para>
    </step>
 
    <step>
     <para>
      Create a database:
-<screen><userinput>createdb testdb</userinput></screen>
+<screen><userinput>/usr/local/pgsql/bin/createdb testdb</userinput></screen>
      Then enter:
-<screen><userinput>psql testdb</userinput></screen>
+<screen><userinput>/usr/local/pgsql/bin/psql testdb</userinput></screen>
      to connect to that database. At the prompt you can enter SQL
      commands and start experimenting.
     </para>