Add notification select all/none button

Also add wording to clarify that crate owners may turn notifications on
or off for each crate.

Author: DSpeckhals

app/controllers/me/index.js

@@ -21,6 +21,12 @@ export default Controller.extend({
   emailNotificationsError: false,
   emailNotificationsSuccess: false,
 
+  setAllEmailNotifications(value) {
+    this.get('ownedCrates').forEach(c => {
+      c.set('email_notifications', value);
+    });
+  },
+
   actions: {
     async saveEmailNotifications() {
       try {
@@ -45,6 +51,12 @@ export default Controller.extend({
         });
       }
     },
+    emailNotificationsSelectAll() {
+      this.setAllEmailNotifications(true);
+    },
+    emailNotificationsSelectNone() {
+      this.setAllEmailNotifications(false);
+    },
     startNewToken() {
       this.store.createRecord('api-token', {
         created_at: new Date(Date.now() + 2000),

app/styles/me.scss

@@ -143,6 +143,10 @@
         }
     }
 
+    .button-container {
+        margin-right: 1rem;
+    }
+
     ul {
         padding: 0;
         @include flex-grow(1);

app/templates/me/index.hbs

@@ -30,9 +30,19 @@
 
   <p>
     To aid detection of unauthorized crate changes, we email you each time a new version of a crate you own is pushed.
-    By receiving and reading these emails, you help protect the Rust ecosystem.
+    By receiving and reading these emails, you help protect the Rust ecosystem. You may also choose to turn these
+    emails off for any of your crates listed below.
   </p>
 
+  <div class='row'>
+    <div class='button-container'>
+      <button type='button' class='yellow-button small' {{action 'emailNotificationsSelectAll'}}>Select All</button>
+    </div>
+    <div class='button-container'>
+      <button type='button' class='yellow-button small' {{action 'emailNotificationsSelectNone'}}>Deselect All</button>
+    </div>
+  </div>
+
   <div class='row'>
     <ul>
       {{#each ownedCrates as |ownedCrate|}}