[model/dataset][m]: introduce Model module containing basic Dataset and TabularData objects (plus tests).

* NB: current Dataset is basic one running off local data.

src/dataset.js

@@ -0,0 +1,43 @@
+this.RECLINE = this.RECLINE || {};
+
+RECLINE.Model = function ($, _, Backbone) {
+  var my = {};
+
+  // A Dataset model.
+  my.Dataset = Backbone.Model.extend({
+    initialize: function(data, rawTabularData) {
+      this.tabularData = new my.TabularData(rawTabularData);
+    }
+
+    // get TabularData object associated with this Dataset
+    //
+    // async (as may involve getting data from the server) implementing standard promise API
+    , getTabularData: function() {
+      var dfd = $.Deferred();
+      dfd.resolve(this.tabularData);
+      return dfd.promise();
+    }
+  });
+
+  // TabularData model
+  my.TabularData = Backbone.Model.extend({
+    getLength: function() { 
+      return this.get('rows').length;
+    }
+    , getRows: function(numRows, start) {
+      if (start === undefined) {
+        start = 0;
+      }
+      if (numRows === undefined) {
+        numRows = 10;
+      }
+      var dfd = $.Deferred();
+      var results = this.get('rows').slice(start, start+numRows);
+      dfd.resolve(results);
+      return dfd.promise();
+    }
+  });
+
+  return my;
+}(this.jQuery, this._, this.Backbone);
+