Fix permissions explanations in CREATE DATABASE and CREATE SCHEMA docs.

These reference pages still claimed that you have to be superuser to create
a database or schema owned by a different role.  That was true before 8.1,
but it was changed in commits aa1110624c and
f91370cd2f to allow assignment of ownership
to any role you are a member of.  However, at the time we were thinking of
that primarily as a change to the ALTER OWNER rules, so the need to touch
these two CREATE ref pages got missed.

doc/src/sgml/ref/create_database.sgml

@@ -46,14 +46,6 @@ CREATE DATABASE <replaceable class="PARAMETER">name</replaceable>
    See <xref linkend="SQL-CREATEUSER">.
   </para>
 
-  <para>
-   Normally, the creator becomes the owner of the new database.
-   Superusers can create databases owned by other users, by using the
-   <literal>OWNER</> clause. They can even create databases owned by
-   users with no special privileges. Non-superusers with <literal>CREATEDB</>
-   privilege can only create databases owned by themselves.
-  </para>
-
   <para>
    By default, the new database will be created by cloning the standard
    system database <literal>template1</>.  A different template can be
@@ -84,9 +76,11 @@ CREATE DATABASE <replaceable class="PARAMETER">name</replaceable>
       <term><replaceable class="parameter">user_name</replaceable></term>
       <listitem>
        <para>
-        The name of the database user who will own the new database,
+        The role name of the user who will own the new database,
         or <literal>DEFAULT</literal> to use the default (namely, the
-        user executing the command).
+        user executing the command).  To create a database owned by another
+        role, you must be a direct or indirect member of that role,
+        or be a superuser.
        </para>
       </listitem>
      </varlistentry>