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
public static Iterator getStyles( )
	{
		return getStyles( new AlphabeticallyComparator( ) );
	}
	/**
	 * @param comparator
	 * @return return styles list sortted with given comparator.
	 */
	public static Iterator getStyles( Comparator comparator )
	{
		List styles = SessionHandleAdapter.getInstance( )
				.getReportDesignHandle( )
				.getAllStyles( );
		Object[] stylesArray = styles.toArray( );
		if ( comparator != null )
		{
			Arrays.sort( stylesArray, comparator );
		}
		return Arrays.asList( stylesArray ).iterator( );
	}
	/**
	 * Checks if two strings have same value.
	 * 
	 * @param str1
	 * @param str2
	 * @return
	 */
	public static boolean isSameString( String str1, String str2 )
	{
		if ( str1 == null && str2 == null )