Ensure extensions don't load until editor is ready

Prior to this change, there were two versions of the code meant to load
extensions from URL query parameters:
- One version reliably waited for the editor to be ready, but looked for
  "ext=" and "proj=" query parameters. This was an old version of the
  JS-Flash interface that was never documented; the docs say to use
  "url=" for both projects and extensions.
- The other version correctly looked for "url=" but did not reliably
  wait for the editor to be ready. This seems to be the most likely
  culprit for reports that extensions sometimes fail to load.

This change unifies those two paths into one which looks for "url=" and
waits for the editor to be ready.

js/scratchx.js

@@ -1,5 +1,6 @@
 // Simulate the bare minimum of the view that exists on the main site
 var Scratch = Scratch || {};
+Scratch.editorIsReady = false;
 Scratch.FlashApp = Scratch.FlashApp || {};
 
 var editorId = "scratch";
@@ -8,7 +9,7 @@ var ShortURL = {
     key : "AIzaSyBlaftRUIOLFVs8nfrWvp4IBrqq9-az46A",
     api : "https://www.googleapis.com/urlshortener/v1/url",
     domain : "http://goo.gl"
-}
+};
 
 function handleEmbedStatus(e) {
     $('#scratch-loader').hide();
@@ -32,7 +33,7 @@ function JSthrowError(e) {
 
 function JSeditorReady() {
     try {
-        handleParameters();
+        Scratch.editorIsReady = true;
         Scratch.FlashApp.$ASobj.trigger("editor:ready");
         return true;
     } catch (error) {
@@ -41,46 +42,10 @@ function JSeditorReady() {
     }
 }
 
-function JSprojectLoaded() {
-    loadExtensionQueue();
-}
-
 function JSshowExtensionDialog() {
     showModal(["template-extension-file", "template-extension-url"]);
 }
 
-var extensionQueue = [];
-function handleParameters() {
-    var project;
-    var queryString = window.location.search.substring(1);
-    var queryVars = queryString.split(/[&;]/);
-    for (var i = 0; i < queryVars.length; i++) {
-        var nameVal = queryVars[i].split('=');
-        switch(nameVal[0]){
-            case 'ext':
-                extensionQueue.push(nameVal[1]);
-                break;
-            case 'proj':
-                project = nameVal[1];
-                break;
-        }
-    }
-    if (project) {
-        Scratch.FlashApp.ASobj.ASloadSBXFromURL(project);
-    }
-    else {
-        loadExtensionQueue();
-    }
-}
-
-function loadExtensionQueue() {
-    for (var i = 0; i < extensionQueue.length; ++i) {
-        var extensionURL = extensionQueue[i];
-        ScratchExtensions.loadExternalJS(extensionURL);
-    }
-    extensionQueue = [];
-}
-
 var flashVars = {
     autostart: 'false',
     extensionDevMode: 'true',
@@ -163,7 +128,7 @@ function sendFileToFlash(file) {
             });
         }
         
-    }
+    };
     fileReader.readAsArrayBuffer(file);
 }
 
@@ -177,7 +142,7 @@ function sendURLtoFlash() {
         urls.push(arguments[i]);
     }
     if (urls.length <= 0) return;
-    if (Scratch.FlashApp.ASobj.ASloadGithubURL !== undefined) {
+    if (Scratch.editorIsReady) {
         $(document).trigger("editor:extensionLoaded", {method: "url", urls: urls});
         showPage(editorId);
         Scratch.FlashApp.ASobj.ASloadGithubURL(urls);
@@ -202,7 +167,6 @@ function loadFromURLParameter(queryString) {
      */
     var paramString = queryString.replace(/^\?|\/$/g, '');
     var vars = paramString.split("&");
-    var showedEditor = false;
     var urls = [];
     for (var i=0; i<vars.length; i++) {
         var pair = vars[i].split("=");
@@ -238,7 +202,7 @@ function getOrCreateFromTemplate(elementId, templateId, elementType, appendTo, w
         $element.appendTo(appendTo)
     }
     return $element;
-};
+}
 
 function showModal(templateId, data) {
     /*
@@ -405,7 +369,7 @@ function showShortUrl(url) {
         var context = {
             longUrl : data.longUrl,
             shortUrl : shortUrl
-        }
+        };
 
         $modal = showModal("template-short-url", context);
         var client = new ZeroClipboard($('button', $modal));
@@ -417,7 +381,7 @@ function JSshowShortUrlFor() {
 }
 
 function decompress(id, done) {
-    var data = {shortUrl: ShortURL.domain + id}
+    var data = {shortUrl: ShortURL.domain + id};
     $.ajax({
         url : ShortURL.api + '?' + $.param({
             key : ShortURL.key,
@@ -452,7 +416,7 @@ $(document).on('click', "[data-action='load-url']", function(e) {
 
 $(document).on('submit', ".url-load-form", function(e) {
     // Load text input value on submit
-    e.preventDefault()
+    e.preventDefault();
     showPage(editorId);
     sendURLtoFlash($('input[type="text"]', this).val());
 });