Merge branch 'sticky-mr-tabs-pinned-nav' into 'master'

Fixed sticky MR tabs positioning when sidebar is pinned

## What does this MR do?

The sticky MR tabs where positioned underneath the pinned sidebar. This fixes that by accounting for the size of the pinned nav.

## Screenshots (if relevant)

![Screen_Shot_2016-10-28_at_09.37.18](/uploads/0d23f2bb0e02d698c012c22c8653afd7/Screen_Shot_2016-10-28_at_09.37.18.png)

## What are the relevant issue numbers?

Closes #23926

See merge request !7167

CHANGELOG.md

@@ -44,6 +44,7 @@ Please view this file on the master branch, on stable branches it's out of date.
   - Fix importing MR comments from GitHub !7139
   - Modify GitHub importer to be retryable !7003
   - Fix and improve `Sortable.highest_label_priority`
+  - Fixed sticky merge request tabs when sidebar is pinned
 
 ## 8.13.1 (2016-10-25)
   - Fix branch protection API. !6215

app/assets/stylesheets/framework/sidebar.scss

@@ -164,6 +164,18 @@
       padding-left: $sidebar_width;
     }
   }
+
+  .merge-request-tabs-holder.affix {
+    @media (min-width: $sidebar-breakpoint) {
+      left: $sidebar_width;
+    }
+  }
+
+  &.right-sidebar-expanded {
+    .line-resolve-all-container {
+      display: none;
+    }
+  }
 }
 
 header.header-sidebar-pinned {