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/core/Module.java
* locale.
	 * <p>
	 * 
	 * @param translation
	 *            new entry of <code>Translation</code> that are to be added
	 *            to the module.
	 */
	public void addTranslation( Translation translation )
	{
		translations.add( translation );
	}
	/**
	 * Drops a Translation from the module.
	 * <p>
	 * 
	 * @param translation
	 *            the translation to be dropped from the module.
	 * 
	 * @return <code>true</code> if the report module contains the given
	 *         translation.
	 */
	public boolean dropTranslation( Translation translation )
	{
		return translations.remove( translation );
	}
	/**
	 * Finds a <code>Translation</code> by the message resource key and the
	 * locale.
	 * <p>
	 *