feat(i18n): support plural and gender special forms

modules/angular2/test/compiler/html_ast_spec_utils.ts

@@ -6,6 +6,8 @@ import {
   HtmlAttrAst,
   HtmlTextAst,
   HtmlCommentAst,
+  HtmlExpansionAst,
+  HtmlExpansionCaseAst,
   htmlVisitAll
 } from 'angular2/src/compiler/html_ast';
 import {ParseError, ParseLocation} from 'angular2/src/compiler/parse_util';
@@ -70,6 +72,19 @@ class _Humanizer implements HtmlAstVisitor {
     return null;
   }
 
+  visitExpansion(ast: HtmlExpansionAst, context: any): any {
+    var res = this._appendContext(ast, [HtmlExpansionAst, ast.switchValue, ast.type]);
+    this.result.push(res);
+    htmlVisitAll(this, ast.cases);
+    return null;
+  }
+
+  visitExpansionCase(ast: HtmlExpansionCaseAst, context: any): any {
+    var res = this._appendContext(ast, [HtmlExpansionCaseAst, ast.value]);
+    this.result.push(res);
+    return null;
+  }
+
   private _appendContext(ast: HtmlAst, input: any[]): any[] {
     if (!this.includeSourceSpan) return input;
     input.push(ast.sourceSpan.toString());