Use local fonts and stop scrollable elements from repainting (#2266)

app/assets/stylesheets/components.scss

@@ -1052,6 +1052,7 @@ a.status__content__spoiler-link {
   overflow-y: scroll;
   overflow-x: hidden;
   flex: 1 1 auto;
+  backface-visibility: hidden;
   -webkit-overflow-scrolling: touch;
 
   &.optionally-scrollable {

app/assets/stylesheets/fonts/montserrat.scss

@@ -1,5 +1,6 @@
 @font-face {
   font-family: 'Montserrat';
+  src: local('Montserrat');
   src: font-url('montserrat/Montserrat-Regular.eot');
   src: font-url('montserrat/Montserrat-Regular.eot?#iefix') format('embedded-opentype'),
   font-url('montserrat/Montserrat-Regular.woff2') format('woff2'),

app/assets/stylesheets/fonts/roboto-mono.scss

@@ -1,5 +1,6 @@
 @font-face {
   font-family: 'Roboto Mono';
+  src: local('Roboto Mono');
   src: font-url('roboto-mono/robotomono-regular-webfont.eot');
   src: font-url('roboto-mono/robotomono-regular-webfont.eot?#iefix') format('embedded-opentype'),
   font-url('roboto-mono/robotomono-regular-webfont.woff2') format('woff2'),

app/assets/stylesheets/fonts/roboto.scss

@@ -1,5 +1,6 @@
 @font-face {
   font-family: 'Roboto';
+  src: local('Roboto');
   src: font-url('roboto/roboto-italic-webfont.eot');
   src: font-url('roboto/roboto-italic-webfont.eot?#iefix') format('embedded-opentype'),
     font-url('roboto/roboto-italic-webfont.woff2') format('woff2'),
@@ -12,6 +13,7 @@
 
 @font-face {
   font-family: 'Roboto';
+  src: local('Roboto');
   src: font-url('roboto/roboto-bold-webfont.eot');
   src: local('Roboto bold'), local('roboto-bold'),
     font-url('roboto/roboto-bold-webfont.eot?#iefix') format('embedded-opentype'),
@@ -25,6 +27,7 @@
 
 @font-face {
   font-family: 'Roboto';
+  src: local('Roboto');
   src: font-url('roboto/roboto-medium-webfont.eot');
   src: font-url('roboto/roboto-medium-webfont.eot?#iefix') format('embedded-opentype'),
     font-url('roboto/roboto-medium-webfont.woff2') format('woff2'),
@@ -37,6 +40,7 @@
 
 @font-face {
   font-family: 'Roboto';
+  src: local('Roboto');
   src: font-url('roboto/roboto-regular-webfont.eot');
   src: font-url('roboto/roboto-regular-webfont.eot?#iefix') format('embedded-opentype'),
     font-url('roboto/roboto-regular-webfont.woff2') format('woff2'),