Updated Twitter bird to latest logo. Added generated sprites to gitignore. Other improvements to theming and sprites

.gitignore

@@ -9,5 +9,6 @@ sass.old
 source.old
 source/_stash
 source/stylesheets/screen.css
+source/images/icon-*.png
 vendor
 node_modules

.themes/classic/sass/base/_theme.scss

@@ -1,6 +1,3 @@
-$noise-bg: image-url('noise.png') top left !default;
-$img-border: inline-image('dotted-border.png') !default;
-
 // Main Link Colors
 $link-color: lighten(#165b94, 3) !default;
 $link-color-hover: adjust-color($link-color, $lightness: 10, $saturation: 25) !default;
@@ -59,7 +56,16 @@ $footer-link-color-hover: darken($footer-color, 25) !default;
 $page-border-bottom: darken($footer-bg, 5) !default;
 
 
-/* Core theme application */
+// Sprites and images
+
+@import "icon/*.png";/**/
+@include all-icon-sprites($dimensions: true);
+
+$noise-bg: image-url('noise.png') top left !default;
+$img-border: inline-image('dotted-border.png') !default;
+
+
+// Core theme application
 
 a {
   color: $link-color;

.themes/classic/sass/base/_utilities.scss

@@ -25,4 +25,3 @@
   $text-color: if($text-color >= 150, $dark, $light);
   @return $text-color;
 }
-

.themes/classic/sass/partials/_sharing.scss

@@ -1,6 +1,3 @@
-@import "icon/*.png";/**/
-@include all-icon-sprites($dimensions: true);
-
 @mixin social-button-bg($icon: false, $color: #333, $img: false) {
   color: $color;
   &:visited, &:hover, &:visited:hover { color: $color; }
@@ -22,12 +19,6 @@
   }
 }
 
-@mixin icon-bg($icon, $align: middle) {
-  display: inline-block;
-  vertical-align: $align;
-  @extend .icon-#{$icon};
-}
-
 .simple-social-button {
   position: relative;
   overflow: hidden;

.themes/classic/sass/partials/sidebar/_twitter.scss

@@ -1,12 +1,20 @@
 #tweets {
   .loading {
-    background: inline-image('bird_32_gray.png') no-repeat center .5em;
+    &:before {
+      content: "";
+      display: block;
+      margin: 0 auto;
+      @extend .icon-twitter-bird;
+    }
     color: darken($sidebar-bg, 18);
     text-shadow: $main-bg 0 1px;
     text-align: center;
-    padding: 2.5em 0 .5em;
-    &.error {
-      background: inline-image('bird_32_gray_fail.png') no-repeat center .5em;
+    padding: .5em 0;
+    .transform &.error {
+      @include rotate(180deg);
+      @include box-shadow(lighten($sidebar-bg, 5) 0 -1px);
+      border-bottom: 0;
+      border-top: 1px solid $sidebar-border;
     }
   }
   p {