Bug 213671 Expose evaluate() method in IReportContext
Need Engine expose evaluate() method in IReportContext interface, this will be used to evaluate global Javascript expression in case there's no resultset bound to current report item.
engine/org.eclipse.birt.report.engine/src/org/eclipse/birt/report/engine/script/internal/ReportContextImpl.java
public String getOutputFormat( )
	{
		return context.getOutputFormat( );
	}
	
	public IRenderOption getRenderOption( )
	{
		return context.getRenderOption( );
	}
	public Object getHttpServletRequest( )
	{
		return getAppContext( ).get( EngineConstants.APPCONTEXT_BIRT_VIEWER_HTTPSERVET_REQUEST );
	}
	public String getMessage( String key )
	{
		return context.getDesign( ).getMessage( key );
	}
	public String getMessage( String key, Locale locale )
	{
		return context.getDesign( ).getMessage( key, locale );
	}
	public String getMessage( String key, Object[] params )
	{
		String msg = context.getDesign( ).getMessage( key );
		if ( msg == null )
			return "";
		return MessageFormat.format( msg, params );
	}
	public String getMessage( String key, Locale locale, Object[] params )
	{