Bug 187213 Provid a writer to serialize design in document without any white space.
Add a new writer for serialize design in document without any withe space.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/writer/IndentableXMLWriter.java
* @throws java.io.IOException
	 *             if write error occurs
	 */
	public IndentableXMLWriter( File outputFile, String signature,
			boolean needMarkLineNumber ) throws IOException
	{
		super( outputFile, signature, needMarkLineNumber );
	}
	/**
	 * Constructor.
	 * 
	 * @param os
	 *            the output stream to which the design file is written.
	 * @param signature
	 *            the unicode signature of the design file
	 * @throws IOException
	 *             if write error occurs
	 */
	public IndentableXMLWriter( OutputStream os, String signature )
			throws IOException
	{
		super( os, signature );
	}
	/**
	 * Constructor.
	 * 
	 * @param os
	 *            the output stream to which the design file is written.
	 * @param signature
	 *            the unicode signature of the design file