Improve importer error messaging

closes #3274

- Ensure that validation errors are always handled by moving them into the
  importer
- Ensure that db errors are handled consistently across sqlite and mysql
- Change the errors to be output in a table, with a short failure notification
- Add tests for 003 importing bad files

ghost/admin/controllers/debug.js

@@ -1,5 +1,6 @@
 var DebugController = Ember.Controller.extend(Ember.Evented, {
     uploadButtonText: 'Import',
+    importErrors: '',
 
     actions: {
         onUpload: function (file) {
@@ -7,6 +8,7 @@ var DebugController = Ember.Controller.extend(Ember.Evented, {
                 formData = new FormData();
 
             this.set('uploadButtonText', 'Importing');
+            this.notifications.closePassive();
 
             formData.append('importfile', file);
 
@@ -20,7 +22,10 @@ var DebugController = Ember.Controller.extend(Ember.Evented, {
             }).then(function () {
                 self.notifications.showSuccess('Import successful.');
             }).catch(function (response) {
-                self.notifications.showAPIError(response);
+                if (response && response.jqXHR && response.jqXHR.responseJSON && response.jqXHR.responseJSON.errors) {
+                    self.set('importErrors', response.jqXHR.responseJSON.errors);
+                }
+                self.notifications.showError('Import Failed');
             }).finally(function () {
                 self.set('uploadButtonText', 'Import');
                 self.trigger('reset');

ghost/admin/templates/-import-errors.hbs

@@ -0,0 +1,7 @@
+{{#if importErrors}}
+<table class="table">
+{{#each importErrors}}
+    <tr><td>{{message}}</td></tr>
+{{/each}}
+</table>
+{{/if}}

ghost/admin/templates/debug.hbs

@@ -28,6 +28,7 @@
                 <fieldset>
                     <div class="form-group">
                         <label>Import</label>
+                        {{partial "import-errors"}}
                         {{gh-file-upload id="importfile" uploadButtonText=uploadButtonText}}
                         <p>Import from another Ghost installation. If you import a user, this will replace the current user & log you out.</p>
                     </div>

ghost/admin/utils/notifications.js

@@ -52,6 +52,8 @@ var Notifications = Ember.ArrayProxy.extend({
 
         if (resp && resp.jqXHR && resp.jqXHR.responseJSON && resp.jqXHR.responseJSON.error) {
             this.showError(resp.jqXHR.responseJSON.error, delayed);
+        } else if (resp && resp.jqXHR && resp.jqXHR.responseJSON && resp.jqXHR.responseJSON.errors) {
+            this.showErrors(resp.jqXHR.responseJSON.errors, delayed);
         } else {
             this.showError(defaultErrorText, delayed);
         }