Bug 195970 Two issues when evaluate a query inlcuding a subquery[07]
Description: Currently, when evaluating a query which includes a subquery, the query will be evaluated twice. The binding of query will pass to subquery twice. If user write a java script such as new Date() and i++. The result of query will be incorrect. Another issue: when write the report document, the binding of query will be written twice and the performance is not good to evalulate it twice.
data/org.eclipse.birt.data/src/org/eclipse/birt/data/engine/impl/ExprManager.java
{
			GroupBindingColumn gcb = (GroupBindingColumn) bindingExprs.get( i );
			if ( entryLevel != OVERALL_GROUP )
			{
				if ( gcb.getGroupLevel( ) > entryLevel )
					continue;
			}
			if( gcb.getBinding( name )!= null )
				return gcb.getBinding( name );
		}
		
		if ( this.autoBindingMap.containsKey( name ))
		{
			return (IBinding)this.autoBindingMap.get( name );
		}	
		
		return null;
		
	}
	/**
	 * @param name
	 * @return
	 * @throws DataException 
	 */
	private IBaseExpression getBindingExpr( String name ) throws DataException
	{
		for ( int i = 0; i < bindingExprs.size( ); i++ )
		{
			GroupBindingColumn gcb = (GroupBindingColumn) bindingExprs.get( i );
			if ( entryLevel != OVERALL_GROUP )