Bug 183919 [Enhancement] add a switch to determine whether to clean viewer image folder when session expires
in current viewer implementation, file in image folder is deleted when its corresponding session expires, could viewer add a switch to allow users to decide whether this deletion operation should be performed.
viewer/org.eclipse.birt.report.viewer/birt/WEB-INF/classes/org/eclipse/birt/report/context/ViewerAttributeBean.java
}
	/**
	 * @return the parameterDefList
	 */
	public Collection getParameterDefList( )
	{
		return parameterDefList;
	}
	/**
	 * @return the displayTexts
	 */
	public Map getDisplayTexts( )
	{
		return displayTexts;
	}
	/**
	 * @return the moduleOptions
	 */
	public Map getModuleOptions( )
	{
		return moduleOptions;
	}
	/**
	 * @return the defaultValues
	 */
	public Map getDefaultValues( )
	{
		return defaultValues;
	}
}