Add nice scroll for sidebar

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

app/assets/javascripts/application.js.coffee

@@ -40,6 +40,7 @@
 #= require shortcuts_issuable
 #= require shortcuts_network
 #= require cal-heatmap
+#= require jquery.nicescroll.min
 #= require_tree .
 
 window.slugify = (text) ->
@@ -104,6 +105,8 @@ if location.hash
 window.addEventListener "hashchange", shiftWindow
 
 $ ->
+  $(".nicescroll").niceScroll(cursoropacitymax: '0.4', cursorcolor: '#FFF', cursorborder: "1px solid #FFF")
+
   # Click a .js-select-on-focus field, select the contents
   $(".js-select-on-focus").on "focusin", ->
     # Prevent a mouseup event from deselecting the input

app/assets/stylesheets/themes/gitlab-theme.scss

@@ -35,7 +35,6 @@
 
     .sidebar-wrapper {
       background: $color-darker;
-      border-right: 1px solid $color-darker;
 
       .sidebar-user {
         background: $color-darker;

app/views/layouts/_page.html.haml

 .page-with-sidebar{ class: nav_sidebar_class }
   = render "layouts/broadcast"
-  .sidebar-wrapper
+  .sidebar-wrapper.nicescroll
     - if defined?(sidebar) && sidebar
       = render "layouts/nav/#{sidebar}"
     - elsif current_user