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
*            style property name
	 * @param value
	 *            default value to set
	 * @throws PropertyValueException
	 *             if value is invalid.
	 */
	public void setDefaultValue( String propName, Object value )
			throws PropertyValueException
	{
		session.setDefaultValue( propName, value );
	}
	/**
	 * Gets the default value of the specified style property.
	 * 
	 * @param propName
	 *            style property name
	 * @return The default value of this style property. If the default value is
	 *         not set, return <code>null</code>.
	 */
	public Object getDefaultValue( String propName )
	{
		return session.getDefaultValue( propName );
	}
	/**
	 * Sets the resource locator for the specified file searching algorithm.
	 * 
	 * @param locator
	 *            the resource locator to be set.
	 */
	public void setResourceLocator( IResourceLocator locator )