title: How to tag a changeset in liquibase to rollback
body: <p>I have configured the maven pluggin for liquibase as specified in <a href="http://www.liquibase.org/manual/maven" rel="noreferrer">maven configuration</a>.<br>
  Now created a changeset like :-</p>
  
  <pre><code>&lt;changeSet id="changeRollback" author="nvoxland"&gt;
    &lt;createTable tableName="changeRollback1"&gt;
       &lt;column name="id" type="int"/&gt;
    &lt;/createTable&gt;
    &lt;rollback&gt;
       &lt;dropTable tableName="changeRollback1"/&gt;
    &lt;/rollback&gt;
  &lt;/changeSet&gt;
  </code></pre>
  
  <p>Created the  sql to update DB using command line :-
  <strong>mvn liquibase:updateSQL</strong></p>
  
  <p>But just want to know how to rollback using a "rollbackTag" parameter.
  i.e. If run the command "<strong>mvn liquibase:rollbackSQL</strong>", what should be the value of "rollbackTag" parameter.</p>
  
  <p>And is it possible to rollback using the changeset id ?</p>