Initial work on import of custom fields from Trello

* start adding import functionality
* Add checkbox type to customFields

client/components/cards/cardCustomFields.jade

@@ -52,6 +52,17 @@ template(name="cardCustomField-number")
         if value
             = value
 
+template(name="cardCustomField-checkbox")
+  if canModifyCard
+    +inlinedForm(classNames="js-card-customfield-checkbox")
+      input(type="checkbox" value=data.value)
+      .edit-controls.clearfix
+        button.primary(type="submit") {{_ 'save'}}
+        a.fa.fa-times-thin.js-close-inlined-form
+  else
+    if value
+      = value
+
 template(name="cardCustomField-currency")
     if canModifyCard
         +inlinedForm(classNames="js-card-customfield-currency")

client/components/cards/cardCustomFields.js

@@ -78,7 +78,26 @@ CardCustomField.register('cardCustomField');
       },
     ];
   }
-}.register('cardCustomField-number'));
+}.register('cardCustomField-checkbox'));
+
+// cardCustomField-checkbox
+(class extends CardCustomField {
+  onCreated() {
+    super.onCreated();
+  }
+
+  events() {
+    return [
+      {
+        'submit .js-card-customfield-checkbox'(event) {
+          event.preventDefault();
+          const value = this.find('input').value !== '';
+          this.card.setCustomField(this.customFieldId, value);
+        },
+      },
+    ];
+  }
+}.register('cardCustomField-checkbox'));
 
 // cardCustomField-currency
 (class extends CardCustomField {