refactor(compiler): cleanup and preparation for integration

- Rename `DirectiveMetadata` into `CompileDirectiveMetadata`, merge
  with `NormalizedDirectiveMetadata` and remove `ChangeDetectionMetadata`
- Store change detector factories not as array but
  directly at the `CompiledTemplate` or the embedded template
  to make instantiation easier later on
- Already analyze variable values and map them
  to `Directive.exportAs`
- Keep the directive sort order as specified in the
  `@View()` annotation
- Allow to clear the runtime cache in `StyleCompiler`
  and `TemplateCompiler`
- Ignore `script` elements to match the semantics of the
  current compiler
- Make all components dynamically loadable and remove
  the previously introduced property `@Component#dynamicLoadable`
  for now until we find a better option to configure this
- Don’t allow to specify bindings in `@View#directives` and `@View#pipes` as this was never supported by the transformer (see below for the breaking change)

BREAKING CHANGE:
- don't support DI bindings in `@View#directives` and `@View@pipes` any more in preparation of integrating the new compiler. Use `@Directive#bindings` to reexport directives under a different token instead.

Part of #3605
Closes #4314

modules/angular2/src/core/metadata.dart

@@ -36,7 +36,7 @@ class Directive extends DirectiveMetadata {
  */
 class Component extends ComponentMetadata {
   const Component({String selector, List<String> properties,
-  List<String> events, Map<String, String> host, bool dynamicLoadable,
+  List<String> events, Map<String, String> host,
   List bindings, String exportAs, String moduleId,
   Map<String, dynamic> queries,
   bool compileChildren, List viewBindings, ChangeDetectionStrategy changeDetection})
@@ -45,7 +45,6 @@ class Component extends ComponentMetadata {
     properties: properties,
     events: events,
     host: host,
-    dynamicLoadable: dynamicLoadable,
     bindings: bindings,
     exportAs: exportAs,
     moduleId: moduleId,