Bug 152828 Add the projectFolder property on module
When user doesn't set the resource folder path in designer, there should be a default working path for Birt to manage the report design and find the related resources. A new property should be added on Module: name: projectFolder type:URL This property only can be given from the open design method from session but should not be set after the module initialized. Concern about the backward compatiblity issue, a new method will be added. Open design with a config argument.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/api/SessionHandle.java
* </ul>
	 * 
	 * @return the application units
	 * 
	 * @see #setApplicationUnits
	 */
	public String getApplicationUnits( )
	{
		return session.getUnits( );
	}
	/**
	 * Sets the rgb color display preference to be used by the application. If
	 * the preference is not set the application will use default
	 * CSS_ABSOLUTE_FORMAT like "RGB(255,0,0)" for a rgb color display value.
	 * The rgbFormat argument is an integer value that may be the following
	 * constants defined in <code>ColorUtil</code>:
	 * <ul>
	 * <li><code>INT_FORMAT</code>
	 * <li><code>HTML_FORMAT</code>
	 * <li><code>JAVA_FORMAT</code>
	 * <li><code>CSS_ABSOLUTE_FORMAT</code>
	 * <li><code>CSS_RELATIVE_FORMAT</code>
	 * </ul>
	 * 
	 * @param rgbFormat
	 *            the rgb color display preference to set.
	 * 
	 * @throws PropertyValueException
	 *             if <code>rgbFormat</code> is not one of the above.
	 *