Better save blocking in intro (closes #1795)

Previous code blocked the button click handler only, not the ⌘S keybinding

js/id/ui/intro.js

@@ -17,6 +17,9 @@ iD.ui.intro = function(context) {
             baseEntities = context.history().graph().base().entities,
             introGraph;
 
+        // Block saving
+        context.inIntro(true);
+
         // Load semi-real data used in intro
         context.connection().toggle(false).flush();
         context.history().reset();
@@ -28,12 +31,6 @@ iD.ui.intro = function(context) {
         context.history().merge(d3.values(iD.Graph().load(introGraph).entities));
         context.background().bing();
 
-        // Block saving
-        var savebutton = d3.select('#bar button.save'),
-            save = savebutton.on('click');
-        savebutton.on('click', null);
-        context.inIntro(true);
-
         d3.select('.background-layer').style('opacity', 1);
 
         var curtain = d3.curtain();
@@ -67,7 +64,6 @@ iD.ui.intro = function(context) {
             context.map().centerZoom(center, zoom);
             window.location.replace(hash);
             context.inIntro(false);
-            d3.select('#bar button.save').on('click', save);
         });
 
         var navwrap = selection.append('div').attr('class', 'intro-nav-wrap fillD');

js/id/ui/save.js

@@ -8,7 +8,7 @@ iD.ui.Save = function(context) {
 
     function save() {
         d3.event.preventDefault();
-        if (!saving() && history.hasChanges()) {
+        if (!context.inIntro() && !saving() && history.hasChanges()) {
             context.enter(iD.modes.Save(context));
         }
     }