Specs: pass the current <script> to the module library init()

sky/specs/modules.md

 Sky Module System
 =================
 
 This document describes the Sky module system.
 
 Overview
 --------
 
 The Sky module system is based on the ``import`` element. In its
 most basic form, you import a module as follows:
@@ skipping 53 matching lines @@
 element, all the libraries are bound to the same name.
 
 At the end of the ``<script>`` block's source, if it parsed correctly
 and completely, the conceptual equivalent of the following code is
 appended (but without affecting the library's list of declarations and
 without any possibility of it clashing with identifiers described in
 the library itself):
 
 ```dart
 class _ { }
-void main() {
+void main(ScriptElement script) {
   LibraryMirror library = reflectClass(_).owner as LibraryMirror;
-  if (library.declarations.containsKey(#init) && library.declarations[#init] is MethodMirror)
-    init();
-  AutomaticMetadata.runLibrary(library, module);
+  if (library.declarations.containsKey(#_init) && library.declarations[#_init] is MethodMirror)
+    _init(script);
+  AutomaticMetadata.runLibrary(library, module, script);
 }
 ```
 
-Then, that ``main()`` function is called.
+Then, that ``main(script)`` function is called, with ``script`` set to
+the ``ScriptElement`` object representing the relevant ``<script>``
+element.
 
 TODO(ianh): decide what URL and name we should give the libraries, as
 exposed in MirrorSystem.getName(libraryMirror.qualifiedName) etc
 
 The ``Module`` class is defined in ``dart:sky`` as follows:
 
 ```dart
 abstract class AbstractModule extends EventTarget {
   AbstractModule({this.url, this.elements});
 
@@ skipping 29 matching lines @@
 }
 
 class Application extends AbstractModule {
   Application({String url, Root elements, this.gestureManager}) :
     super(url: url, elements: elements); // O(1)
   external String get title; // O(1)
   external void set title(String newValue); // O(1)
   final GestureManager gestureManager;
 }
 ```