Bug 189706 Enhance computed column aggregation function handling in UI.
Due to the issue discussed in 189705, current computed column aggregation builder in data set editor has bugs to extend: 1.When new a computed column, the aggregation argument field cannot be correctly set. 2.The argument field cannot be correct grayed out when user select a aggregation function without arguments 3.The available aggregation function list is incomprehensive 4.Some aggregation function cannot be set to model(say, weightedAve).
data/org.eclipse.birt.data/src/org/eclipse/birt/data/engine/expression/ExpressionProcessor.java
try
		{
			ExpressionInfo exprInfo;
			for ( int i = 0; i < exprArray.length; i++ )
			{
				baseExpression = (IBaseExpression) exprArray[i];
				if ( baseExpression instanceof IConditionalExpression )
				{
					compileConditionalExpression( (IConditionalExpression) baseExpression,
							helper,
							rsPopulator,
							arrayType,
							currentGroupLevel[i],
							context );
				}
				else if ( baseExpression instanceof IScriptExpression )
				{
					exprInfo = new ExpressionInfo( (IScriptExpression) baseExpression,
							arrayType,
							currentGroupLevel[i],
							true );
					baseExpression.setHandle( helper.compileExpression( exprInfo,
							context ) );
				}
			}
		}
		finally
		{
			Context.exit( );