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
/**
	 * @param name
	 * @param baseExpr
	 */
	void addAutoBindingExpr( String name, IBaseExpression baseExpr )
	{
		autoBindingExprMap.put( name, baseExpr );
		this.autoBindingMap.put( name, new Binding( name, baseExpr ) );
	}
	/**
	 * @param name
	 * @return expression for specified name
	 * @throws DataException 
	 */
	public IBaseExpression getExpr( String name ) throws DataException
	{
		IBaseExpression baseExpr = getBindingExpr( name );
		if ( baseExpr == null )
			baseExpr = getAutoBindingExpr( name );
		return baseExpr;
	}
	/**
	 * 
	 * @param name
	 * @return
	 * @throws DataException
	 */
	public IBinding getBinding( String name ) throws DataException
	{
		for ( int i = 0; i < bindingExprs.size( ); i++ )