Initial commit of Effen reactive framework experiment for Sky

sky/examples/stocks-fn/stocklist.dart

+part of stocksapp;
+
+class Stocklist extends FixedHeightScrollable {
+
+  List<Stock> stocks;
+
+  Stocklist({
+    Object key,
+    this.stocks
+  }) : super(key: key, itemHeight: 80.0, height: 800.0, minOffset: 0.0);
+
+  List<Node> renderItems(int start, int count) {
+    var items = [];
+    for (var i = 0; i < count; i++) {
+      items.add(new StockRow(stock: stocks[start + i]));
+    }
+
+    return items;
+  }
+}