title: liqubase: generate sql script from changelog xml without db connection
body: <p>I have a liqubase changelog.xml. It includes few "include file" with changes. 
  For example, base script with creating a table and another one with adding a new field to this table.</p>
  
  <p>Could I get sql-script with one "create table..." statement, which include all fields. And I don't want to connect to DB. Just use liquibase xml files and jar libs.</p>
  
  <p>Version liquibase - 3.5.5.</p>
  
  <p>I tried to run do this command:
  java -jar liquibase-core-3.5.5.jar --url=offline:mssql?outputLiquibaseSql=true --changeLogFile="changelog.xml" --outputFile="all.sql" updatesql</p>
  
  <p>changelog.xml:</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="UTF-8"?&gt;
  &lt;databaseChangeLog
          xmlns="http://www.liquibase.org/xml/ns/dbchangelog/1.9"
          xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
          xsi:schemaLocation="http://www.liquibase.org/xml/ns/dbchangelog/1.9
           http://www.liquibase.org/xml/ns/dbchangelog/dbchangelog-1.9.xsd"&gt;
      &lt;include file="base.sql" relativeToChangelogFile="true"/&gt;
      &lt;include file="changelog_20180719.xml" relativeToChangelogFile="true"/&gt;
  &lt;/databaseChangeLog&gt;
  </code></pre>
  
  <p>but all.sql contains only sql from first included file (base.sql)</p>
  
  <p>Thanks</p>