title: Liquibase call procedure without database specification
body: <p>Is the way to call stored procedure without database specification? For example:</p>
  
  <ol>
  <li><code>&lt;changeSet author="name" id="id1" dbms="mysql"&gt;
      &lt;sql&gt;
          EXEC procedure_name('some_string_value')
      &lt;/sql&gt;
  &lt;/changeSet&gt;</code></li>
  <li><code>&lt;changeSet author="name" id="id2" dbms="oracle"&gt;
      &lt;sql&gt;
          EXECUTE procedure_name('some_string_value')
      &lt;/sql&gt;
  &lt;/changeSet&gt;</code></li>
  <li><code>&lt;changeSet author="name" id="id3" dbms="postgresql"&gt;
      &lt;sql&gt;
          SELECT fun_name('some_string_value')
      &lt;/sql&gt;
  &lt;/changeSet&gt;</code></li>
  </ol>
  
  <p>I need avoid database conditions because I call this procedure in different places. Is there a way to achieve this with implementing db condition in one place?  </p>