Bug 121687 Exception throws when export data in table which inside a grid cell.
Description: Exception throws when export data in table which inside a grid cell. Steps to reproduce: 1. insert a grid. 2. insert one table to one grid cell. 3. insert another table to the other grid cell. 4. export data in two tables. Expected result: Data are exported. Actual result: Exception in: ReportEngineService.getMetaData( )
engine/org.eclipse.birt.report.engine/src/org/eclipse/birt/report/engine/parser/EngineIRVisitor.java
report.addStyle( styleName, style );
		return styleName;
	}
	protected String getElementProperty( ReportElementHandle handle, String name )
	{
		return getElementProperty( handle, name, false );
	}
	protected String getElementProperty( ReportElementHandle handle,
			String name, boolean isColorProperty )
	{
		FactoryPropertyHandle prop = handle.getFactoryPropertyHandle( name );
		if ( prop != null && prop.isSet( ) )
		{
			if ( isColorProperty )
			{
				return prop.getColorValue( );
			}
			return prop.getStringValue( );
		}
		return null;
	}
	String getElementColorProperty( ReportElementHandle handle, String name )
	{
		FactoryPropertyHandle prop = handle.getFactoryPropertyHandle( name );
		if ( prop != null && prop.isSet( ) )
		{
			return prop.getColorValue( );
		}
		return null;
	}