Bug 120218 Right click menu option to apply theme.
We should support the following right click menu. -- User right clicks int he report design layout area. -- The following menu items needs to be supported Theme --> Apply Theme -->Theme1 -->Theme2 ( similar to Apply style menu option )
UI/org.eclipse.birt.report.designer.core/src/org/eclipse/birt/report/designer/util/DEUtil.java
* @param path
	 *            the path to convert
	 * @return The relative path based on the base path if it is possible, or
	 *         the original path
	 * 
	 */
	public static String getRelativedPath( String basePath, String path )
	{
		
		
		return URIUtil.getRelativePath( new File( basePath ).getParent( ),
				new File( path ).getParent( ) )
				+ "/" + new File( path ).getName( );
	}
	/**
	 * Returns the handle of the action of the given element.
	 * 
	 * @param element
	 *            the element handle
	 * @return the handle of the action, or null if the element is not a proper
	 *         type
	 */
	public static ActionHandle getActionHandle( ReportItemHandle element )
	{
		ActionHandle actionHandle = null;
		if ( element instanceof LabelHandle )
		{
			actionHandle = ( (LabelHandle) element ).getActionHandle( );
		}
		else if ( element instanceof DataItemHandle )