feat(core): separate refs from vars.

Introduces `ref-` to give a name to an element or a directive (also works for `<template>` elements), and `let-` to introduce an input variable for a `<template>` element.

BREAKING CHANGE:
- `#...` now always means `ref-`.
- `<template #abc>` now defines a reference to the TemplateRef, instead of an input variable used inside of the template.
- `#...` inside of a *ngIf, … directives is deprecated.
  Use `let …` instead.
- `var-...` is deprecated. Replace with `let-...` for `<template>` elements and `ref-` for non `<template>` elements.

Closes #7158

Closes #8264

modules/angular2/test/compiler/offline_compiler_util.ts

@@ -1,5 +1,6 @@
 import {print, IS_DART} from 'angular2/src/facade/lang';
 import {OutputEmitter} from 'angular2/src/compiler/output/abstract_emitter';
+import {Console} from 'angular2/src/core/console';
 
 import {
   OfflineCompiler,
@@ -48,8 +49,8 @@ function _createOfflineCompiler(xhr: MockXHR, emitter: OutputEmitter): OfflineCo
   var htmlParser = new HtmlParser();
   var normalizer = new DirectiveNormalizer(xhr, urlResolver, htmlParser);
   return new OfflineCompiler(
-      normalizer,
-      new TemplateParser(new Parser(new Lexer()), new MockSchemaRegistry({}, {}), htmlParser, []),
+      normalizer, new TemplateParser(new Parser(new Lexer()), new MockSchemaRegistry({}, {}),
+                                     htmlParser, new Console(), []),
       new StyleCompiler(urlResolver), new ViewCompiler(new CompilerConfig(true, true, true)),
       emitter);
 }