feat(typings): allow defining custom namespace for bundle

Allows declaring a bundle's namespace in generated typings file,
which should correspond to the global object representing the module
inside its bundle.

BREAKING CHANGE
    The router was previously exported as ng.router in the 
    angular.sfx.dev.js bundle, but now it is exported as ngRouter.

Closes #2948

Closes #3544

docs/typescript-definition-package/templates/type-definition.template.html

@@ -30,7 +30,7 @@
 // ***********************************************************
 {% for alias, module in doc.moduleDocs %}
 {%- if module.references.length %}
-// Angular depends transitively on these libraries.
+// {$ alias $} depends transitively on these libraries.
 // If you don't have them installed you can install them using TSD
 // https://github.com/DefinitelyTyped/tsd
 {%- endif %}
@@ -39,7 +39,7 @@
 {% block staticDeclarations %}{% endblock %}
 {% for alias, module in doc.moduleDocs %}
 {$ commentBlock(module.doc, 1) $}
-declare module ng {
+declare module {$ module.namespace $} {
 
   {%- for export in module.doc.exports -%}
   {%- if export.content -%}
@@ -75,7 +75,7 @@ declare module ng {
 }
 
 declare module "{$ alias $}" {
-  export = ng;
+  export = {$ module.namespace $};
 }
 
 {% endfor %}