Add support for complex ids in @data references

lib/handlebars/compiler/compiler.js

@@ -301,7 +301,15 @@ Compiler.prototype = {
 
   DATA: function(data) {
     this.options.data = true;
-    this.opcode('lookupData', data.id);
+    if (data.id.isScoped || data.id.depth) {
+      throw new Handlebars.Exception('Scoped data references are not supported: ' + data.original);
+    }
+
+    this.opcode('lookupData');
+    var parts = data.id.parts;
+    for(var i=0, l=parts.length; i<l; i++) {
+      this.opcode('lookup', parts[i]);
+    }
   },
 
   STRING: function(string) {
@@ -749,7 +757,7 @@ JavaScriptCompiler.prototype = {
   //
   // Push the result of looking up `id` on the current data
   lookupData: function(id) {
-    this.push(this.nameLookup('data', id, 'data'));
+    this.push('data');
   },
 
   // [pushStringParam]

lib/handlebars/compiler/printer.js

@@ -121,7 +121,7 @@ Handlebars.PrintVisitor.prototype.PARTIAL_NAME = function(partialName) {
 };
 
 Handlebars.PrintVisitor.prototype.DATA = function(data) {
-  return "@" + data.id;
+  return "@" + this.accept(data.id);
 };
 
 Handlebars.PrintVisitor.prototype.content = function(content) {