Saves post title on focus blur if status is draft

Closes #6656
- adds an action to update the title
- checks if the post title has changed and is a draft and sends a silent + background save action
- includes the action on the focus-out event on the post title

Author: jeffjewiss

core/client/app/mixins/editor-base-controller.js

@@ -398,6 +398,25 @@ export default Mixin.create({
             return transition.retry();
         },
 
+        updateTitle() {
+            let currentTitle = this.model.get('title');
+            let newTitle = this.model.get('titleScratch').trim();
+
+            if (currentTitle === newTitle) {
+                return;
+            }
+
+            if (this.get('model.isDraft') && !this.get('model.isNew')) {
+                // this is preferrable to setting hasDirtyAttributes to false manually
+                this.model.set('title', newTitle);
+
+                this.send('save', {
+                    silent: true,
+                    backgroundSave: true
+                });
+            }
+        },
+
         toggleReAuthenticateModal() {
             this.toggleProperty('showReAuthenticateModal');
         }

core/client/app/templates/editor/edit.hbs

@@ -1,7 +1,7 @@
 <section class="gh-view">
     <header class="view-header">
         {{#gh-view-title classNames="gh-editor-title" openMobileMenu="openMobileMenu"}}
-            {{gh-trim-focus-input type="text" id="entry-title" placeholder="Your Post Title" value=model.titleScratch tabindex="1" focus=shouldFocusTitle}}
+            {{gh-trim-focus-input type="text" id="entry-title" placeholder="Your Post Title" value=model.titleScratch tabindex="1" focus=shouldFocusTitle focus-out="updateTitle" }}
         {{/gh-view-title}}
         <section class="view-actions">
             <button type="button" class="post-settings" title="Post Settings" {{action "openSettingsMenu"}}>