Bug 132515 Expression like "Toltal.rank(Tolta.ave(row[a]),ture,Null,1)" is return an error
Description: Add an expression like "Toltal.rank(Tolta.ave(row[a]),ture,Null,1)" is return an error.The nesting "Toltal" seem not to be work. Step to reproduce: 1.new a datasource and dataset 2.drag the dataset to layout veiw for a table 3.set a group on the table 4.Insert a data into the group header with the expression e.g. "Toltal.rank(Tolta.ave(row[a]),ture,Null,1)" Actual result: An error was thrown out Expected result: It should work correctly in order to support some requirments
data/org.eclipse.birt.data/src/org/eclipse/birt/data/engine/executor/transform/IExpressionProcessor.java
{
	/**
	 * computed column expression
	 */
	public final static int COMPUTED_COLUMN_EXPR = 0;
	/**
	 * filter column expression
	 */
	public final static int FILTER_COLUMN_EXPR = 1;
	/**
	 * group expression
	 */
	public final static int GROUP_COLUMN_EXPR = 2;
	/**
	 * filter expression on group
	 */
	public final static int FILTER_ON_GROUP_EXPR = 3;
	/**
	 * sort expression on group
	 */
	public final static int SORT_ON_GROUP_EXPR = 4;
	/**