Add support for depthed resolution of data fields

lib/handlebars/base.js

@@ -223,5 +223,7 @@ export var logger = {
 export function log(level, obj) { logger.log(level, obj); }
 
 export var createFrame = function(object) {
-  return Utils.extend({}, object);
+  var frame = Utils.extend({}, object);
+  frame._parent = object;
+  return frame;
 };

lib/handlebars/compiler/compiler.js

@@ -310,11 +310,7 @@ Compiler.prototype = {
 
   DATA: function(data) {
     this.options.data = true;
-    if (data.id.isScoped || data.id.depth) {
-      throw new Exception('Scoped data references are not supported: ' + data.original, data);
-    }
-
-    this.opcode('lookupData');
+    this.opcode('lookupData', data.id.depth);
     var parts = data.id.parts;
     for(var i=0, l=parts.length; i<l; i++) {
       this.opcode('lookup', parts[i]);

lib/handlebars/compiler/javascript-compiler.js

@@ -403,8 +403,12 @@ JavaScriptCompiler.prototype = {
   // On stack, after: data, ...
   //
   // Push the data lookup operator
-  lookupData: function() {
-    this.pushStackLiteral('data');
+  lookupData: function(depth) {
+    if (!depth) {
+      this.pushStackLiteral('data');
+    } else {
+      this.pushStackLiteral('this.data(data, ' + depth + ')');
+    }
   },
 
   // [pushStringParam]

lib/handlebars/runtime.js

@@ -77,6 +77,12 @@ export function template(templateSpec, env) {
       }
       return data;
     },
+    data: function(data, depth) {
+      while (data && depth--) {
+        data = data._parent;
+      }
+      return data;
+    },
     merge: function(param, common) {
       var ret = param || common;