feat(mail): Change spam icon and add spam button to mail interface

UI/WebServerResources/js/Mailer/Mailbox.service.js

@@ -207,7 +207,7 @@
       }
       else if (this.type == 'junk') {
         this.$displayName = l('JunkFolderName');
-        this.$icon = 'thumb_down';
+        this.$icon = 'gpp_bad';
       }
       else if (this.type == 'templates') {
         this.$displayName = l('TemplatesFolderName');

UI/WebServerResources/scss/components/icon/icon.scss

@@ -11,10 +11,9 @@ $icon-badge-size: 2 * $baseline-grid;
   font-family: 'Material Icons';
   font-style: normal;
   font-weight: 400;
-  src: url('../fonts/MaterialIcons-Regular.eot'); /* For IE6-8 */
-  src: local('Material Icons'),
-       local('MaterialIcons-Regular'),
-       url('../fonts/MaterialIcons-Regular.woff2') format('woff2'),
+  /* No local() sources: always use the bundled font so an outdated
+     Material Icons font installed on the OS can't shadow it. */
+  src: url('../fonts/MaterialIcons-Regular.woff2') format('woff2'),
        url('../fonts/MaterialIcons-Regular.woff') format('woff'),
        url('../fonts/MaterialIcons-Regular.ttf') format('truetype');
 }