Bug 173236 NPE is thrown when opening a design file that is created by a higher version BIRT
1. New a report, switch to xml-source view. 2. Edit the version number in line 2, from 3.2.10 to 3.2.11 and save. 3. Close the report and reopen it. The xml-source view is opened automatically. Switch to lay-out view, there's an error message window, and NPE is thrown in error-log view. When user is trying to open a design file that is created by a higher version BIRT, model will throw an exception and stop parsing the report design file. UI should 1. Prevent the NPE 2. Telling user that he is using a higher version design file that this build does not support. (Catch the exception and reflect the message in the exception to end user)
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/parser/DesignParserException.java
/**
	 * The element id is duplicate.
	 */
	public static final String DESIGN_EXCEPTION_DUPLICATE_ELEMENT_ID = MessageConstants.DESIGN_PARSER_EXCEPTION_DUPLICATE_ELEMENT_ID;
	/**
	 * The default element is not the same type of template element.
	 */
	public static final String DESIGN_EXCEPTION_INCONSISTENT_TEMPLATE_ELEMENT_TYPE = MessageConstants.DESIGN_PARSER_EXCEPTION_INCONSISTENT_TEMPLATE_ELEMENT_TYPE;
	/**
	 * Error code indicating template parameter definition have no default
	 * element.
	 */
	public static final String DESIGN_EXCEPTION_MISSING_TEMPLATE_PARAMETER_DEFAULT = MessageConstants.DESIGN_PARSER_EXCEPTION_MISSING_TEMPLATE_PARAMETER_DEFAULT;
	/**
	 * The simple list property has no definition in the element.
	 */
	
	public static final String DESIGN_EXCEPTION_WRONG_SIMPLE_LIST_TYPE = MessageConstants.DESIGN_PARSER_EXCEPTION_WRONG_SIMPLE_LIST_TYPE;
	
	/**
	 * Constructs the design parser exception with the error code.
	 * 
	 * @param errCode
	 *            the error condition
	 */
	public DesignParserException( String errCode )
	{
		super( errCode );